Blender Git Loki

Get workspace mode from the workspace view-layer

While this probably isn't the final solution we'll go with, it's nicer
as current one, which was basically broken. So consider this as
temporary solution.

It also allows testing how changing workspace changes mode & active
object, but only by having the workspaces use different view-layers.

Decided to remove WorkSpace.mode for now. If we need to bring it back,
we'll have to version patch it anyway.