Simplify ApiErrorLogger.instance

[Masynchin]

Aim of this PR is to simplify ApiErrorLogger.instance by replacing ..pure[IO].ifM.. with just a whenA. Both ifM and whenA takes effect by name, so no penalty for whenA usage over ifM.

I also extracted logger calls into a separate function, so that ApiErrorLogger.instance shortens to:

def instance(using Logger[IO]): HttpApp[IO] => HttpApp[IO] = http =>
  Kleisli: req =>
    http(req).flatTap: res =>
      logError(req, res).whenA(isResponseError(res))

I hope this change simplifies the code so it is easier to maintain. Looking for CI tests, because of my inability to running tests locally

[lenguyenthanh]

Thanks, this looks great! I believe this works and better than the previous version.

Unfortunately we don't have test for this. But I guess it is quite easy to add tests for this.