Repository commits/branches/tags page: Serve potentially cached data

Created by: umpox

We should try to serve cached data on the commit/branches/tags page because this data is already loaded through the revisions selector (which currently already caches responses).

1. Go to https://sourcegraph.com/github.com/sourcegraph/sourcegraph
2. Navigate between the commit/branches/tags pages e.g. https://sourcegraph.com/github.com/sourcegraph/sourcegraph/-/commits
3. This data is very similar to the data loaded in the revisions selector. We might be able to share responses here to speed up performance for both journeys.