New Hyperion feature: Layers

Short update post.

Over the long weekend, I worked on a new feature I'd been thinking about adding to Hyperion: Layers. With this, we can allow entities to have per-Layer property overrides. For example, would could have a "Summer" layer, and a "Winter" layer where we have ground textures swap to a more seasonally appropriate attire (snow).

My working sample is having baked light for some different times of day. All the indirect light here is baked as well as reflection probes.