Abort if test definitions exist but no tests were actually
constructed from the configuration.

This can happen if the regex does not match any of the files
in the reference solutions directory.

[App] Add log level setting to partmesh.

See merge request ogs/ogs!3012

[PL/Output] Escape {} to fix bug in error message.

See merge request ogs/ogs!3013

Change of OGS version only affects frontpage and navigation tree.
The navigation tree is a single html embedded into every page.
This helps in better CDN caching and faster uploads on Netlify.

Is used by the Doxygen job to populate the git version info.