Try to use context/system class loader if the application class loader is not able to load a logging mdc class

[tobiasstadler]

What does this PR do?

Alternative to #2369

Checklist

• This is an enhancement of existing features, or a new feature in existing plugins
  • I have updated CHANGELOG.asciidoc
  • I have added tests that prove my fix is effective or that my feature works
  • Added an API method or config option? Document in which version this will be introduced
  • I have made corresponding changes to the documentation

[github-actions]

👋 @tobiasstadler Thanks a lot for your contribution!

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• Reason: The PR is not allowed to run in the CI yet

• Start Time: 2022-01-27T18:07:24.195+0000

• Duration: 5 min 15 sec

• Commit: 6d50e9e

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[felixbarny]

Likely to be superseded by #2412

[tobiasstadler]

As #2369 also solves my problem, I am fine with closing this in favor of #2412