tests/test-gendoc-pt_BR.t

formatter: populate ctx from repo and node value

This will basically replace the fm.contexthint() API. I originally thought
this would be too complicated, and I wrote 8399438bc7ef "formatter: provide
hint of context keys required by template" because of that. However, I had
to add a similar mechanism for fctx templates, and the overall machinery
became way simpler than my original patch.

The test output slightly changed as {author} is no longer available in
the {manifest} context, which isn't the point this test targeted on.

#require docutils gettext

  $ $TESTDIR/check-gendoc pt_BR
  checking for parse errors