gl-renderer: improve GL ES and EGL feature logging

I've been annoyed by the long lists of EGL and GL extensions. They are only useful if you actually know which extensions GL-renderer would like. IOW, it's mostly useless chatter.

This MR moves those extension lists into a new log scope, so that if one wants to see them, they are still available. Just not cluttering the normal logs. The new log scope is intended for more than just this.

To make sure we don't miss anything, we now log the features we use explicitly for both GL ES and EGL. This should make them much more obvious to the reader, and it's shorter than the old way.

Plus a couple more logging additions.