[GTK4] Guard new dialog API behind a 4.10 version check

[ptziegler]

This restricts the GTK4-specific dialogs to only be executed when the system is using at least GTK 4.10. In all other cases, the (deprecated) implementation that was removed with the following commits has been restored:

• FontDialog: 10567bb
• FileDialog: 4179dc7
• DirectoryDialog: 2e61b4b

[github-actions]

Test Results

   502 files  ±0     502 suites  ±0   9m 27s ⏱️ - 1m 39s
 4 334 tests ±0   4 320 ✅ ±0   14 💤 ±0  0 ❌ ±0 
16 575 runs  ±0  16 466 ✅ ±0  109 💤 ±0  0 ❌ ±0 

Results for commit b046ad3. ± Comparison against base commit cd8bb13.

♻️ This comment has been updated with latest results.

[akurtakov]

I have just tested(on gtk4-4.16.5-2.fc41) this patch with ControlExample Directory/FileDialog are fine but FontDialog crashes with:

Exception in thread "main" java.lang.IllegalArgumentException: Argument cannot be null
	at org.eclipse.swt.SWT.error(SWT.java:4913)
	at org.eclipse.swt.SWT.error(SWT.java:4847)
	at org.eclipse.swt.SWT.error(SWT.java:4818)
	at org.eclipse.swt.graphics.Font.<init>(Font.java:78)
	at org.eclipse.swt.widgets.FontDialog.open(FontDialog.java:214)
	at org.eclipse.swt.examples.controlexample.DialogTab.createButtonSelected(DialogTab.java:221)
	at org.eclipse.swt.events.SelectionListener$1.widgetSelected(SelectionListener.java:83)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:286)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:91)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:5857)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1652)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:5067)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4519)
	at org.eclipse.swt.examples.controlexample.ControlExample.main(ControlExample.java:240)

[ptziegler]

I have just tested(on gtk4-4.16.5-2.fc41) this patch with ControlExample Directory/FileDialog are fine but FontDialog crashes with:

You're right. I only tested the implementation with Snipet133, so I didn't notice the case in which the dialog is called without an initial font. I've added an additional NULL check in case no font data has been set.

[akurtakov]

Thanks for the fast changes! This one is good to go in.