Migrate ConfirmEdit to use template

Zuul now has support to add jobs after a template has been applied.
Normalize ConfirmEdit to use the 'extension-checks' template.

Noop change.

Change-Id: I762ef16425fe787d845ef28f203d6ffe62929531
Trigger unittests for ConfirmEdit

And move the python jobs to from 'check-voter' to 'check' and 'test'.

Change-Id: Iaf0bfdc256a864ae71946a996046414f8526e964