Status page: Indicate whether there are enabled modules with `schema_version` of `-1`

[klonos]

This is a thing that shouldn't happen under normal circumstances, however, as discussed in #6438 and in this Zulip thread, it does happen (and has some odd UX side effects when it does).

I believe that it would be helpful to at least point out in the site status report when this happens, and be listing the modules that get into that situation. Perhaps if people start reporting these problems, we might be able to see a pattern and get to the bottom of why it happens.

[nattywebdev]

Thanks for recording this. It's a real problem that I encounter but only when upgrading from D7 to B, and always on only a few contrib modules. No particular pattern that I can discern, as it's rarely the same modules that cause it in my experience. Next time I have it I will record it here.

[bugfolder]

I agree with this check. It was puzzling when it happened to a site I was doing, and it's regularly puzzling to people who report it in Zulip. One wonders how many non-Zulip devs just ignore it as "one of those puzzling things but the site works fine otherwise."

[izmeez]

@klonos Thank you for opening this issue. I recently encountered this problem on a straight backdrop built site when aligning changes between live and dev involving transfer of database from one to another where on one the module was enabled and on the other it had not been enabled. The problem was not immediately apparent and may have emerged after update.php was required with core and contrib module updates. Through the zulip chat I was directed to check the database system table for modules with a status = 1 and schema_version = -1. After the the schema_version was manually fixed and caches flushed the problem was resolved. An indicator in the UI could be helpful.