Remote's labels are not entirely under our control as the part before
":" is the *owner* of the source repo => introduce additional "owned"
fixture to handle this case, as it may diverge from the "user" role if
running the tests against an organisation.
Can't really assume we can get the github logins "user" or "reviewer"
to run the test suite remotely, so add an indirection and backronym
those to *roles* instead. The local test suite has identical roles &
logins, but the remote version does not.
Also use the "other" role for any random user, and don't create its
partner up-front.
Also renamed the self-reviewer user to self_reviewer, that's a bit
less weird when dealing with e.g. ini files.
This is the preparation of an attempt to make these tests work with
both a local github mock (in-memory) and a remote actual github.
Move a bunch of fixtures relying on the specific github
implementation (and odoo-as-library access) to the "local" plugin,
including splitting the "repo" fixture.
The specific fixtures will likely have to be adjusted as the
remote endpoint is fleshed out.
