Tidy up popup layouts

- Settings: labels in one column and switches and number buttons lined
  up in another, with margins inside the panel
- Log: title and margins; text no longer touches the panel edge
- Sync result: error list centred under its header, which now reads
  Errors instead of CatchedErrors
- About: text wraps inside the panel instead of running under the
  scrollbar
- Character select: wider panel, so the right column of characters is
  no longer right next to the scrollbar

sync_window.gd

@@ -144,7 +144,7 @@ func on_sync_finished(data_received: Dictionary) -> void:
 	
 	if data_received.catched_errors != null && data_received.catched_errors.size() > 0:
 		catched_errors_vbox.visible = true
-		make_list(data_received.catched_errors, catched_errors_vbox, "CatchedErrors")
+		make_list(data_received.catched_errors, catched_errors_vbox, "Errors")
 	
 	# Hide separators that don't have a visible section after them
 	# The structure is: RestartSyncButton -> VSeparator6 -> VBox -> Separator -> VBox -> Separator -> ...