Option to apply baked layer/mask as standard image

[ucupumar]

Pre-Flight checklist

• [x] Did you check to see if this issue already exists?
• [x] This is a single feature request. (Do not put multiple feature requests in one issue)

Describe The Feature Request Below

There's a case where users only want to bake AO/Edge Detect as a base for painting, so the rebake option becomes irrelevant. There should be an option to apply the baked layer/mask as a standard image layer/mask.

This becomes even more useful when baking any layer type is fully implemented (#65).