Blender Git Loki

UI: Theme tweak to selected animation channels

We have the problem that it's very hard to see which animation channels are selected. This is a very small tweak to make it more obvious, using the same text highlight color as the Outliner.

Really it should be overhauled to be more exactly like the Outliner, but this is just a quick fix to make it reasonably visible.

Differential Revision: https://developer.blender.org/D6708

Reviewed by Julian Eisel