Support per-viewport collection visibility options.
Note 1: There is no way to show a collection that was not visible before
due to depsgraph. Otherwise we would risk having all the collections in
the depsgraph and I believe this is not the idea.
An alternative would be to have a new depsgraph for viewports that are
not local. Something to keep in mind if we do per-viewport current frame
in the future.
So for now what we do is to only allow collections visibility to be
disabled/hidden in this mode.
Note 2: hide_viewport (the eye icon) doesn't really matter for
depsgraph. So after the merge we can still ignore it to show the
collections locally in a viewport with no problems for the depsgraph.
Reviewers: brecht, sergey
Subscribers: billreynish
Related task: T61327
Differential Revision: https://developer.blender.org/D5611
92736a7b75