Implement externally extensible logging configuration

[chshersh]

Current approach for logging extensions is not externally extensible. It's great to have more flexible logging configuration:

• https://github.com/serokell/log-warper/blob/fb0ea8451db9a832baf619f59d937b723c983415/log-warper/src/Logw/Configuration/Type.hs#L68

For reference see discussion here:

• https://github.com/serokell/log-warper/pull/108#discussion_r183030304