Add UI for pausing attribute signaling.

Status Job ID Name Coverage
  External
passed cdash

failed ghostflow-branch-check-master

pending smtk@master-junction-osx-shared-release+remus
passed smtk@master-kerbin-windows-shared-release+examples+remus

00:10:24

passed smtk@master-moho-linux-shared-relwithdebinfo+examples+private+remus

00:02:46

passed smtk@master-moho-linux-shared-relwithdebinfo+examples+python3+remus+vtk

00:02:59

passed smtk@master-moho-linux-shared-relwithdebinfo+examples+remus

00:02:47

failed smtk@master-moho-linux-shared-relwithdebinfo+examples+remus+vtk

00:01:48

passed smtk@master-norkit-osx-shared-release+examples+matplotlib

00:09:22

passed smtk@master-praxis-windows-shared-release

00:05:02

passed smtk@master-talosiv-osx-shared-release+examples+matplotlib

00:02:59

passed smtk@master-tatooine-osx-shared-release+examples+matplotlib

00:03:06

passed smtk@master-tatooine-osx-shared-release+examples+matplotlib+private

00:03:43

passed cdash