Add ability for shortcut action to be disabled instead of removed when unregistering

[Yoooi0]

So that we can register/unregister actions dynamically without loosing configured actions in bindings.
Somehow need to be able to differentiate deprecated vs dynamic actions. Deprecate via migrations?

MultiFunPlayer/MultiFunPlayer/Input/IShortcutManager.cs

Lines 71 to 79 in 9d6a9a8

	public void UnregisterAction(IShortcutActionDescriptor actionDescriptor)
	{
	AvailableActions.Remove(actionDescriptor);
	_actionBuilders.Remove(actionDescriptor);
	foreach (var (gesture, assignedActions) in Bindings)
	foreach (var action in assignedActions.Where(a => actionDescriptor.Equals(a.Descriptor)).ToList())
	assignedActions.Remove(action);
	}

Also plugin registered actions will be lost each restart.