Switch to structured json logging

[baszoetekouw]

Manage's current log files are hard to parse because of custom messaging and multi-line logs. Please switch to structured (json) logging so it get easier to parse the messages to backend systems.

Sprint boot seems to support both Elastic and Logstash formats (https://spring.io/blog/2024/08/23/structured-logging-in-spring-boot-3-4). The ECS/Elastic format seems most flexible, so please use that,

[baszoetekouw]

eduID and Invite work correctly (via logback).

[phavekes]

See OpenConext/OpenConext-Invite@bf6232e and OpenConext/OpenConext-deploy@8ec336b