[FIX] postgres: collation detection

[Armin-FalDiS]

Description

Fix collation detection to use postgres itself instead of glibc which might be incorrect on some systems.

Linked Issues

The mismatch causes odev to be stuck in a loop of asking

[!] Database odev has a collation version mismatch.                                                                                                                                                                                                                                                                                                                                                                                               
[?] Do you want to refresh collation for all affected Odev databases? (Y/n)

forever and ever.

Compliance

• I have read the contribution guide
• I made sure the documentation is up-to-date both in doctrings and the docs directory
• I have added or modified unit tests where necessary
• I have added new libraries to the requirements.txt file, if any
• I have incremented the version number according the versioning guide
• The PR contains my changes only and no other external commit