Moved several render traits from Mods.RA to Common

What the title said.
This trait fits in with the other general purpose With* traits, and really ought to be used in more places:
* The tiberium silos in TS should be using this instead of using `RenderBuildingSilo` with a non-standard sequence configuration (it defines the overlay as the primary idle animation).
* The custom RA harvester artwork for ore levels could be replaced with an overlay to dramatically reduce the number of custom artwork frames and remove the hacky `ImagesByFullness` from `RenderHarvester`.