Uniform logging schema

[Janmtbehrens]

Uniform logging should be implemented in openslides-go so services using openslides-go can use its logging system as a single feature source

[ostcar]

This should be fixed with #151

Please reopen, if there is there are still problems with the format

[Janmtbehrens]

Are debug messages meant to be standard size and not bold? My understanding is that every (dev-environment) message should be bold.

I executed the dev setup without the OPENSLIDES_DEVELOPMENT flag set to 1. This seems to be the deciding factor on whether or not your logging system uses the development-layout or production-layout.
Doing so causes a message like this to appear:

2026-02-26T08:52:32:000 ERROR msg="Error: (...)"

The timestamp is expanded and the message is in JSON format, which is good, but neither the timestamp or logging level are in JSON format. This needs to be fixed or explained