Resume provenance content-revision layer processing through the revision journal client

We want to resume processing of revisions in the provenance database using the new journal client.

To do so, we will:

• give mmca access to the main archive through a SSH reverse tunnel
• give mmca access to the journal through read-only, non-privileged journal credentials
• upgrade swh.provenance on mmca
• restart mmca's content-revision layer using the journal client

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Migrated from T4408 (view on Phabricator)