Respect PHP and Drupal error logging

[grasmash]

Is your feature request related to a problem? Please describe.
I found it very confusing that despite configuring both Drupal and PHP to NOT display deprecation warnings, I continued to see them locally. I wasted a good bit of time discovering https://github.com/acquia/blt/blob/main/settings/logging.settings.php#L18 which completely overrides those settings. This feels a bit heavy handed.

Describe the solution you'd like
At the least, prominently document this behavior. Ideally it should be displayed at run time in the error log. If I saw a notice in the error log that said something like "BLT has set error_reporting to E_ALL" then I would have resolved the issue much faster.

Describe alternatives you've considered
Alternatively, we could just stop overriding the error level.

[grasmash]

This would be good:

error_log("BLT is overriding the error_reporting, display_errors, and display_startup_errors settings in logging.settings.php.");

But only if it doesn't execute for every single PHP process. Not sure if there's away to do it less frequently, like only when cache is cleared.