[Suggestion][Editor] Clear assignment button in hot keys menu

[GigaLem]

I don't know how this was missed but we might as well address it, the only way to clear assignments in the editor's hotkey menu is the clear all button. You can't exactly clear one specific key, you have to reassign all of the hotkeys or edit a text file to remove assignments.

So I might as well make the topic to have it addressed and applied.