Module Metadata and fine settings

[ponceta]

FEATURE

The users should be able to check some module metadata

• SRID
• Language
• Version
• Install date
• Upgrade date

And handle some module specific parameters

• webgis
• extensions
• custom_yaml
• my_super_metadata
• ...

These information have to be stored in the module metadata.

These information can be reused to propose correct .qgs language or providing a default language code where it is useful (see webgis views for example).

[3nids]

what do you mean by metadata?
it's already stored in the pum_migrations table and accessible via API.

#153 has brought a few improvements in this aspect

[3nids]

fixed