Create a most active developers block based on versioncontrol data

It seems that currently these blocks are only used on the global commit view page. If that gets nuked in #782618: Create a global git commit view, then we may not have a place to display there, even though they are probably more interesting than the global commit view itself.

I moved #850146: Create git analogue to most active projects blocks into a separate issue since that's going to be the responsibility of versioncontrol_project, and it's better to keep each issue as self-contained as possible.

Moving to the right project. This may or may not be relevant anymore after project metrics discussion is done.

Actually, this doesn't have anything to do with projects, so it really belongs in vcapi itself, not in vc_project. We could probably use a better component for this -- the choices in this queue are a bit narrow. ;)

That said, yeah, it might be dependent on sampler in some way, I'm not sure yet.

If not, it's blocked on #782586: Merge views module into the main versioncontrol module.

So, either way, this is blocked on something else... hence postponed.

re-opening as start commit of views is about to be committed

The base of views integration is committed, but I really do not know how to do group by on views(without depending on another module) nor I reviewed the sampler module, but I have a query to paste here:

SELECT users.name AS users_name, users.uid AS users_uid, COUNT(versioncontrol_operations.vc_op_id) as ranking
FROM versioncontrol_operations versioncontrol_operations 
INNER JOIN users users ON versioncontrol_operations.uid = users.uid
WHERE versioncontrol_operations.uid <> 0
GROUP BY versioncontrol_operations.uid
ORDER BY ranking DESC

Since #970256: Introduce additional fields on operations table for capturing user mappings, now we need two queries, one for author_uid and the other for committer_uid. Naturally we can just skip one of them if we only want to show one of those profiles.

not sure if we still want to define "most active", but changing title and category in this bug triage

This should be focus on event data(not on operations), and based on activity related code(gsoc-activity feature branch), so let's re-think that later.

(changed during triage)