Allow selecting and copying pinned chat message

Using the context menu only though, because the label won't take
keyboard focus no matter how much it's told to do so. Which means that
the canvas copy shortcut will always take precedence.

ChangeLog

@@ -16,6 +16,7 @@ Unreleased Version 2.2.0-pre
  * Fix: Make exported palettes not start using the exported location to save changes to. Thanks xxxx for reporting.
  * Feature: Allow muting notifications for a window. Thanks Blozzom for suggesting.
  * Fix: Enable the lock session menu option properly, it remained stuck disabled in some cases before.
+ * Feature: Allow selecting and copying text from the pinned message (through the context menu, it doesn't take keyboard shortcuts.) Thanks Bluestrings for suggesting.
 
 2023-07-31 Version 2.2.0-beta.6
  * Fix: Don't forget account password when entering a wrong session password.

src/desktop/chat/chatwidgetpinnedarea.cpp

@@ -11,12 +11,15 @@ ChatWidgetPinnedArea::ChatWidgetPinnedArea(QWidget *parent) :
 	setVisible(false);
 	setOpenExternalLinks(true);
 	setWordWrap(true);
+	setTextInteractionFlags(Qt::TextBrowserInteraction);
 	setStyleSheet(QStringLiteral(
-		"background: #232629;"
-		"border-bottom: 1px solid #2980b9;"
-		"color: #eff0f1;"
-		"padding: 3px;"
-					  ));
+		"QLabel {"
+		"	background: #232629;"
+		"	border-bottom: 1px solid #2980b9;"
+		"	color: #eff0f1;"
+		"	padding: 3px;"
+		"}"
+	));
 }
 
 void ChatWidgetPinnedArea::setPinText(const QString &safetext)