Add Ability to Lock Brushes/Models

[Monkey Frog Studio]

I'd like to see added the ability to lock brushes, models, lights, anything you place in a viewport. The idea is to make it so it cannot be selected/moved, etc. When designing a game in the editor, it gets busy in the viewports and it's very easy to attempt to select something and accidently select something else. Or you attempt to select something and you cannot because something is on top of what you want to select. Locked objects would not be selectable. For all intents-and-purposes, they would be 'invisible' to the cursor (even though visible in the viewport). This way, for example, you could lock all your brushes in a particular area and do a drag-select of all lights, etc.

Locking and unlocking could be a tick box on the scene side panel when an object or objects are selected. Ticked to lock, unticked to unlock.