Rename Action: "Isolate Layer" -> "Isolate Active Layer"
Two reasons:
1.) It better describes the feature. We aren't isolating a specific layer,
we are continually isolating whichever layer is active.
2.) We'll be adding a second mode soon, "Isolate Active Group".
(cherry picked from commit 44e3f62e110cf46d09bbdf25a98c2b92f2a0243f)