Blender Git Loki

Fix Face Set Visibility operator using wrong active Face Set

The Face Set visibility operator was using the last active Face Set
updated by the paint cursor, so when the paint cursor is not used (when
using a filter or a transform tool), the active Face Set was not updating
and it was hidding the wrong Face Set based on the last cursor position
with a brush tool active. Now the Face Set Visitility operator has an
invoke callback wich forces a active vertex and face set update
regardless of the active tool, so it should always work correctly.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D8580