Add deprecation notice to a duplicate method of class Window

[Chubercik]

• Fixes Duplicated Code in Window::move_to_foreground() and Window::grab_focus() #82936.
• Closes Remove duplication of methods' code of class Window using an alias #87093.

This pull request adds a deprecation warning to the Window::move_to_foreground() method, as internally it contains the same code as the Window::grab_focus() method.

In a future version of Godot (4.3? 4.4? 5.x?) said method ought to be removed, however, to maintain compatibility a deprecation warning should suffice for now.

Note: If this is not the right way to purge duplicates from the codebase I am more than willing to re-do it once I've been shown the proper way.

[Sauermann]

Please squash the commits into a single one as described in the PR-workflow
https://docs.godotengine.org/en/stable/contributing/workflow/pr_workflow.html#the-interactive-rebase

[Sauermann]

Code looks correct.
Question is, if the linked issue is enough in order to justify this deprecation.

[akien-mga]

Given that there is a DisplayServer.window_move_to_foreground, it's expected that there should be a Window.move_to_foreground counterpart. It's similar in most situations where there's a Node counterpart to a Server API.

grab_focus was likely added as a counterpart to the Control API (which doesn't share an inheritance with Window aside from Node, but some of their API is indeed similar).

So yeah I'm not sure what to do here. CC @bruvzg

[Chubercik]

If we end up deeming both of these methods useful, how about making one of them an alias for the other?

[akien-mga]

If we end up deeming both of these methods useful, how about making one of them an alias for the other?

Yes that's a good idea. And this can be pointed out in both their description, linking to the other method using the [method move_to_foreground] syntax.

Additionally deprecating could still be an option though, but I'd like to have @bruvzg's input on this.

[akien-mga]

Thanks!