Draft: Resolve "Layer: avoid LayerComposer when possible"

Closes #441

TODO

• Handle flipped textures in the absence of the LayerComposer
• Handle color space discrepancies in the absence of the LayerComposer
• Handle offset/scale
• Make TileMesh understand non-render target elevation textures
• Handle texture inheritance without the need of LayerComposer
• Handle preloading textures without the need of LayerComposer