tests: add commit hashes to log commands in rebase tests
Commit hashes are a useful way to ensure the content of commits made in the
tests are not changing, even if we don't query every aspect of every commit.
(And some properties, like extras, are rarely printed at all.)
Many of the rebase log -G calls didn't show hashes; by adding hashes to places
that weren't showing them we can help protect those tests from unwanted
changes.
Differential Revision: https://phab.mercurial-scm.org/D1650
#require docutils gettext
$ $TESTDIR/check-gendoc sv
checking for parse errors