Remove various warnings for serial when using Java 21

src/main/java/frost/storage/perst/PerstString.java

@@ -26,6 +26,9 @@ public class PerstString extends Persistent {
 
 	private String value;
 
+	public PerstString() {
+	}
+
 	public PerstString(String value) {
 		this.value = value;
 	}

src/main/java/frost/storage/perst/messagearchive/ArchiveMessageStorageRoot.java

@@ -28,6 +28,9 @@ public class ArchiveMessageStorageRoot extends Persistent {
 
 	private Index<PerstFrostArchiveBoardObject> boardsByName;
 
+	public ArchiveMessageStorageRoot() {
+	}
+
 	public ArchiveMessageStorageRoot(Storage storage) {
 		boardsByName = storage.createIndex(String.class, true);
 	}

src/main/java/frost/storage/perst/messagearchive/PerstFrostArchiveBoardAttachment.java

@@ -29,6 +29,9 @@ public class PerstFrostArchiveBoardAttachment extends Persistent {
 	private String privKey;
 	private String description;
 
+	public PerstFrostArchiveBoardAttachment() {
+	}
+
 	public PerstFrostArchiveBoardAttachment(String name, String pubKey, String privKey, String description) {
 		this.name = name;
 		this.pubKey = pubKey;

src/main/java/frost/storage/perst/messagearchive/PerstFrostArchiveBoardObject.java

@@ -31,6 +31,9 @@ public class PerstFrostArchiveBoardObject extends Persistent {
 	private Index<PerstFrostArchiveMessageObject> messageIndex;
 	private Index<PerstFrostArchiveMessageObject> messageIdIndex;
 
+	public PerstFrostArchiveBoardObject() {
+	}
+
 	public PerstFrostArchiveBoardObject(Storage storage, String name) {
 		boardName = name;
 

src/main/java/frost/storage/perst/messagearchive/PerstFrostArchiveFileAttachment.java

@@ -28,6 +28,9 @@ public class PerstFrostArchiveFileAttachment extends Persistent {
 	private long size;
 	private String chkKey;
 
+	public PerstFrostArchiveFileAttachment() {
+	}
+
 	public PerstFrostArchiveFileAttachment(String name, long size, String chkKey) {
 		this.name = name;
 		this.size = size;

src/main/java/frost/storage/perst/messagearchive/PerstFrostArchiveMessageObject.java

@@ -48,8 +48,11 @@ public class PerstFrostArchiveMessageObject extends Persistent {
 	private String content;
 	private String publicKey;
 
-	private Link<PerstFrostArchiveBoardAttachment> boardAttachments;
-	private Link<PerstFrostArchiveFileAttachment> fileAttachments;
+	private transient Link<PerstFrostArchiveBoardAttachment> boardAttachments;
+	private transient Link<PerstFrostArchiveFileAttachment> fileAttachments;
+
+	public PerstFrostArchiveMessageObject() {
+	}
 
 	public PerstFrostArchiveMessageObject(Storage storage, String messageId, String inReplyTo, long dateAndTime,
 			int msgIndex, String fromName, String subject, String recipientName, int signatureStatus, boolean isReplied,

src/main/java/frost/storage/perst/messages/MessageContentStorageRoot.java

@@ -33,6 +33,9 @@ public class MessageContentStorageRoot extends Persistent {
 	private Index<PerstString> signatureByMsgOid;
 	private Index<PerstAttachments> attachmentsByMsgOid;
 
+	public MessageContentStorageRoot() {
+	}
+
 	public MessageContentStorageRoot(Storage storage) {
 		contentByMsgOid = storage.createIndex(int.class, true);
 		publickeyByMsgOid = storage.createIndex(int.class, true);

src/main/java/frost/storage/perst/messages/MessageStorageRoot.java

@@ -31,6 +31,9 @@ public class MessageStorageRoot extends Persistent {
 
 	private Index<PerstIdentitiesMessages> identitiesMessages;
 
+	public MessageStorageRoot() {
+	}
+
 	public MessageStorageRoot(final Storage storage) {
 		boardsByName = storage.createIndex(String.class, true);
 		boardsById = storage.createIndex(int.class, true);

src/main/java/frost/storage/perst/messages/PerstAttachments.java

@@ -31,6 +31,9 @@ public class PerstAttachments extends Persistent {
 	private IPersistentList<PerstBoardAttachment> boardAttachments;
 	private IPersistentList<PerstFileAttachment> fileAttachments;
 
+	public PerstAttachments() {
+	}
+
 	public PerstAttachments(Storage storage, IPersistentList<PerstBoardAttachment> otherBoardAttachments,
 			IPersistentList<PerstFileAttachment> otherFileAttachments) {
 		if (otherBoardAttachments != null && otherBoardAttachments.size() > 0) {

src/main/java/frost/storage/perst/messages/PerstBoardAttachment.java

@@ -29,6 +29,9 @@ public class PerstBoardAttachment extends Persistent {
 	private String privKey;
 	private String description;
 
+	public PerstBoardAttachment() {
+	}
+
 	public PerstBoardAttachment(String name, String pubKey, String privKey, String description) {
 		this.name = name;
 		this.pubKey = pubKey;

src/main/java/frost/storage/perst/messages/PerstFileAttachment.java

@@ -28,6 +28,9 @@ public class PerstFileAttachment extends Persistent {
 	private long size;
 	private String chkKey;
 
+	public PerstFileAttachment() {
+	}
+
 	public PerstFileAttachment(String name, long size, String chkKey) {
 		this.name = name;
 		this.size = size;

src/main/java/frost/storage/perst/messages/PerstFrostBoardObject.java

@@ -51,6 +51,9 @@ public class PerstFrostBoardObject extends Persistent {
 	private IPersistentList<PerstFrostUnsentMessageObject> unsentMessagesList;
 	private IPersistentList<PerstFrostUnsentMessageObject> draftMessagesList;
 
+	public PerstFrostBoardObject() {
+	}
+
 	public PerstFrostBoardObject(Storage storage, String boardName, int boardId) {
 		this.boardName = boardName;
 		this.boardId = boardId;

src/main/java/frost/storage/perst/messages/PerstFrostMessageObject.java

@@ -55,6 +55,9 @@ public class PerstFrostMessageObject extends Persistent {
 	private int idLinePos;
 	private int idLineLen;
 
+	public PerstFrostMessageObject() {
+	}
+
 	public PerstFrostMessageObject(String messageId, String inReplyTo, long dateAndTime, int msgIndex,
 			String invalidReason, String fromName, String subject, String recipientName, int signatureStatus,
 			boolean isDeleted, boolean isNew, boolean isReplied, boolean isJunk, boolean isFlagged, boolean isStarred,

src/main/java/frost/storage/perst/messages/PerstFrostUnsentMessageObject.java

@@ -37,15 +37,18 @@ public class PerstFrostUnsentMessageObject extends Persistent {
 	private int idLinePos;
 	private int idLineLen;
 
-	private Link<PerstFrostUnsentBoardAttachment> boardAttachments;
-	private Link<PerstFrostUnsentFileAttachment> fileAttachments;
+	private transient Link<PerstFrostUnsentBoardAttachment> boardAttachments;
+	private transient Link<PerstFrostUnsentFileAttachment> fileAttachments;
 
 	private String content;
 
 	private long timeAdded;
 
 	private long sendAfterTime;
 
+	public PerstFrostUnsentMessageObject() {
+	}
+
 	public PerstFrostUnsentMessageObject(Storage storage, String messageId, String inReplyTo, String fromName,
 			String subject, String recipientName, int idLinePos, int idLineLen, String content, long timeAdded,
 			long sendAfterTime) {
@@ -119,6 +122,9 @@ public class PerstFrostUnsentFileAttachment extends Persistent {
 		private long size;
 		private String chkKey;
 
+		public PerstFrostUnsentFileAttachment() {
+		}
+
 		public PerstFrostUnsentFileAttachment(String name, long size, String chkKey) {
 			this.name = name;
 			this.size = size;
@@ -147,6 +153,9 @@ public class PerstFrostUnsentBoardAttachment extends Persistent {
 		private String privKey;
 		private String description;
 
+		public PerstFrostUnsentBoardAttachment() {
+		}
+
 		public PerstFrostUnsentBoardAttachment(String name, String pubKey, String privKey, String description) {
 			this.name = name;
 			this.pubKey = pubKey;

src/main/java/frost/storage/perst/messages/PerstIdentitiesMessages.java

@@ -29,6 +29,9 @@ public class PerstIdentitiesMessages extends Persistent {
 	private String uniqueName;
 	private IPersistentList<PerstFrostMessageObject> messagesFromIdentity;
 
+	public PerstIdentitiesMessages() {
+	}
+
 	public PerstIdentitiesMessages(Storage storage, String uniqueName) {
 		this.uniqueName = uniqueName;
 		messagesFromIdentity = storage.createScalableList();