Disable/Remove METAINFOCACHE?

Due to https://bugs.kde.org/show_bug.cgi?id=226353 METAINFOCACHE was introduced 14 years ago to speed up project overview.

When trying to do mass changes (... -> …) Lokalize crashes after a few files in https://invent.kde.org/sdk/lokalize/-/blob/master/src/project/updatestatsjob.cpp?ref_type=heads#L80.

Also when trying to introduce filterable branches for PO Summit (see: !153) I don't really get the code to change metainfocache DB (and new attribute "dbVersion") like expected.

So have been working with #define NOMETAINFOCACHE for a few days and cannot see any noticeable drawbacks (somehow it feels even a bit faster).

General performance has been improved (SSD drives) and maybe we can

• introduce a build option and disable by default or
• remove this "obsolete" code at all.