Improve server settings editor and status bar

Use icons for all server settings buttons. Rearrange and group buttons.

Show buttons in disabled state when they are not useable instead of hiding them.

Remove checker background from server settings list.

Overhaul hotkeys, also show hotkeys in the tooltips:
- Enter: add command
- Alt+Enter: update command (previously M)
- Alt+Up/Down: move command up/down (previously no hotkey)
- Delete: delete command

Don't activate command lineinput when selecting, moving or deleting elements, as this prevents the listbox from accepting the delete hotkey.

Fix server settings listbox being active while file dialog is open.

Ensure extra editor dragbar area matches the respective toolbar size.

Remove spacing on the left side of extra editors to improve alignment.

Increase status bar button sizes and make them consistent.

Use `enum` to track active extra editor instead of using multiple `bool`s.

Disable extra editor buttons when tile picker is shown, as the extra editors are not rendered in this case.

src/engine/textrender.h

@@ -64,6 +64,7 @@ enum
 
 namespace FontIcons {
 // Each font icon is named according to its official name in Font Awesome
+MAYBE_UNUSED static const char *FONT_ICON_PLUS = "+";
 MAYBE_UNUSED static const char *FONT_ICON_LOCK = "\xEF\x80\xA3";
 MAYBE_UNUSED static const char *FONT_ICON_MAGNIFYING_GLASS = "\xEF\x80\x82";
 MAYBE_UNUSED static const char *FONT_ICON_HEART = "\xEF\x80\x84";
@@ -79,6 +80,8 @@ MAYBE_UNUSED static const char *FONT_ICON_BAN = "\xEF\x81\x9E";
 MAYBE_UNUSED static const char *FONT_ICON_CIRCLE_CHEVRON_DOWN = "\xEF\x84\xBA";
 MAYBE_UNUSED static const char *FONT_ICON_SQUARE_MINUS = "\xEF\x85\x86";
 MAYBE_UNUSED static const char *FONT_ICON_SQUARE_PLUS = "\xEF\x83\xBE";
+MAYBE_UNUSED static const char *FONT_ICON_SORT_UP = "\xEF\x83\x9E";
+MAYBE_UNUSED static const char *FONT_ICON_SORT_DOWN = "\xEF\x83\x9D";
 
 MAYBE_UNUSED static const char *FONT_ICON_HOUSE = "\xEF\x80\x95";
 MAYBE_UNUSED static const char *FONT_ICON_NEWSPAPER = "\xEF\x87\xAA";
@@ -112,6 +115,9 @@ MAYBE_UNUSED static const char *FONT_ICON_IMAGE = "\xEF\x80\xBE";
 MAYBE_UNUSED static const char *FONT_ICON_MUSIC = "\xEF\x80\x81";
 MAYBE_UNUSED static const char *FONT_ICON_FILE = "\xEF\x85\x9B";
 
+MAYBE_UNUSED static const char *FONT_ICON_PENCIL = "\xEF\x8C\x83";
+MAYBE_UNUSED static const char *FONT_ICON_TRASH = "\xEF\x87\xB8";
+
 MAYBE_UNUSED static const char *FONT_ICON_ARROWS_LEFT_RIGHT = "\xEF\x8C\xB7";
 MAYBE_UNUSED static const char *FONT_ICON_ARROWS_UP_DOWN = "\xEF\x81\xBD";
 MAYBE_UNUSED static const char *FONT_ICON_CIRCLE_PLAY = "\xEF\x85\x84";