API: Update query modules for MCR

API: Update query modules for MCR

MCR deprecated the Revision class in favor of the broadly similar
RevisionRecord, and more interestingly added the concept of multiple
content "slots" to revisions.

Thus, prop=revisions, prop=deletedrevisions, and so on gain a parameter
to specify which slots are wanted. When this new parameter is not
specified (and any content-related props are specified), a warning about
the legacy format will be issued.

The rest of the modules just needed to call methods or use constants on
RevisionRecord instead of Revision. ApiQueryDeletedrevs wasn't touched,
since it has been deprecated since 1.25 anyway.

This also updates a few non-query modules that don't depend on details
of editing, diffing, or viewing MCR revisions that haven't been figured
out yet.

Bug: T200568
Change-Id: I1327d1784f5cedb006cd74df834cf9a560a77a5d