Add Create Image from Clipboard to FileSystem dock

[KoBeWi]

godot.windows.editor.dev.x86_64_SfyBFqBJVe.mp4

For now it hacks on top of duplicate dialog.
I plan to rework that dialog once #78744 is merged.

btw I also considered adding this functionality to EditorResourcePicker, but the problem is that it would make the texture embedded by default, which is not ideal.

[torcado194]

Wonderful! I would love to see this feature built-in.

This is actually the first feature I made as a godot plugin:

Would it be possible to bind this action to Ctrl+V?
I would also love if there was an additional option to replace the currently selected image with the clipboard image. I have this bound to Ctrl+Shift+V in my plugin, I probably use it more often than the basic paste.

[KoBeWi]

I just wanted to add a basic functionality after we got the new clipboard feature. It can later be expanded upon.
The PR is somewhat consistent with how filesystem dock works (simply adds another Create New option), while what you suggest does not really have precedent and requires more discussion.