database: include UpdatedAt in Repo LastMinChanged field

Created by: keegancsmith

LastMinChanged was introduced to detect changes in a repository over time. Previously it only took into account the clone changing. However, we also want to know if the metadata has changed, such as the name or private/public status. This commit additionally includes repositories if update_at is newer than LastMinChanged.

Note: the test required some updates to work. Most notably our test helpers don't set updated_at (unlike our syncer). To get them to set updated_at required lots of changes to unrelated tests. So instead we manualy update updated_at. We also switch to comparing based on repo names instead of the repo struct since the helper won't include the correct UpdatedAt field.