Bring consistency into logging

[pleshakov]

As a developer for NGF
I want to make all of our log output consistent with the logging guidelines
So that the log lines that already exist are not used as an example for how to make log output and make the logs more inconsistent in future.

For each log line in the code:

• Make sure it is consistent with the guidelines -- https://github.com/nginxinc/nginx-kubernetes-gateway/blob/main/docs/developer/logging-guidelines.md

As part of that, make sure errors are either handled or logged.