Rename Input::set_disable_input() to Input::set_input_disabled()

[Lexyth]

Changed disable_input to input_disabled in input.h and input.cpp, as it's state, not an action.
Changed set_disable_input to set_input_disabled in input.h and input.cpp to reflect the change to the identifier.

[Lexyth]

Fairly certain the name should be changed to set_input_disabled_override, too, but changing anything public about Window seems like a rabbit hole I'd rather avoid.

[Nintorch]

The change looks quite simple and the name makes sense, it makes it more consistent with other methods (set_mouse_mode_override_enabled, set_joy_motion_sensors_enabled, see also #111679 (comment) ), and the method doesn't seem to be exposed to the scripts, so it's not a breaking change. LGTM!

[Nintorch]

@Lexyth Hello, there seems to be a merge conflict with the scene/debugger/scene_debugger.cpp file, may I ask if you can rebase your PR, merge the commits together and give the resulting commit a more descriptive name (for example, Rename Input::set_disable_input() to Input::set_input_disabled()) whenever you can, please? The instructions on how to do those can be found here: https://contributing.godotengine.org/en/latest/pull_requests/creating_pull_requests.html#updating-your-branch :)