[Data rearchitecture] Implement recent revisions for timeslices

[gabina]

What this PR does

This PR implements a new RevisionStatTimeslice class to replace the existing RevisionStat timeslice. Since raw revisions are no longer available, we calculate recent revisions based on the latest timeslices.

• For course-level recent revisions, we use the most recent CourseWikiTimeslices for the course. As we cannot assume a fixed timeslice duration, we compute a daily ratio of revisions (revisions per day) and multiply it by the REVISION_TIMEFRAME to determine the total count.
• For user-level recent revisions, we rely on the latest CourseUserWikiTimeslices for the course and user. This approach differs from the original implementation as it only considers revisions relevant to the course. In contrast, the previous method included all user edits, even those from namespaces like user talk, which are not directly pertinent to the course.

Screenshots

Before:
Recent revisions was 0

After:
Recent revisions for course

Recent revision for editors

Open questions and concerns

As noted, the recent revision counts generated by the timeslice-based approach are not identical to the previous implementation. In particular, the user-level recent revision counts differ, leading to some discrepancies in the web application. For example:

To address this, we may want to consider updating the tooltip to provide additional clarity regarding the changes in how revisions are calculated.

[Formasitchijoh]

@gabina a fix has been made to the failure you are having in your build. Please Could you update your branch with master