Implement `MessageFactory`-namespaced logger registry (blocked by `2.24.1` release)

[vy]

Port #2936 fixing #2933 in 2.x to main when 2.24.1 is released.

[ppkarwasz]

We should probably abstain as much as possible from using helper methods in log4j-api, because these give a rather unnatural dependency of log4j-core on a recent version of log4j-api.
I would put the revamped LoggerRegistry in log4j-kit.