Fix a regression with matching repository and review group conditions.
Review Request #1611 — Created March 11, 2019 and updated
The recent access controls added for repository and review group choices for conditions resulted in a regression when matching these. Both of these implemented queryset logic that assumed access to an `HttpRequest`, but this wasn't the case during matching. The attempts caused a `KeyError`, which was getting caught at the wrong level and transformed into an entirely different form of error. This fixes the regression by changing the querysets yet again. Now, if we're in a condition matching mode (as indicated by a new `matching` state set for the choices), we revert back to a simpler query that just filters on the Local Site. Testing Done: Verified the failure in new unit tests, and that the issue is now fixed. Reviewed at https://reviews.reviewboard.org/r/10435/