Provide conditional wait awaiting for the modal dialog to appear in UI

tests

to avoid this potential error when it is too slow (happens regularly on
CI)
```
  1) Camel properties auto-completion support
       "after all" hook for "code diagnostic is working":
     NoSuchElementError: no such element: Unable to locate element:
{"method":"css selector","selector":".monaco-dialog-box"}
```

Signed-off-by: Aurélien Pupier <apupier@redhat.com>

src/ui-test/utils/testUtils.ts

@@ -161,6 +161,14 @@ export async function closeEditor(title: string, save?: boolean) {
 	const dirty = await new TextEditor().isDirty();
 	await new EditorView().closeEditor(title);
 	if (dirty) {
+		await VSBrowser.instance.driver.wait(() => {
+			try {
+				new ModalDialog();
+				return true;
+			} catch {
+				return false;
+			}
+		});
 		const dialog = new ModalDialog();
 		if (save) {
 			await dialog.pushButton('Save');