reporting: enable logging & skipping of unrecognised probes, detectors in digest generation

[leondz]

Summary

If an unknown probe or detector is encountered in report_digest, due for example to version mismatches, it fails. Would be cool if it didn't.

Basic example

Here, the plugin name's shifted from ContinueSlursReclaimedSlurs80 to ContinueSlursReclaimedSlursMini`:

(garak) 10:04:50 x1:~/dev/garak [main] $ python -m garak.analyze.report_digest hymba.jsonl > hymba.html
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/Users/lderczynski/dev/garak/garak/analyze/report_digest.py", line 292, in <module>
    digest_content = compile_digest(report_path, taxonomy=taxonomy)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/lderczynski/dev/garak/garak/analyze/report_digest.py", line 201, in compile_digest
    getattr(pm, probe_class).__doc__
    ^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'garak.probes.continuation' has no attribute 'ContinueSlursReclaimedSlurs80'. Did you mean: 'ContinueSlursReclaimedSlurs'?

Would be cool if we notified on stderr and in the report, and continued on, instead of breaking like this.

Motivation

To enable reports to be generated even if not all the source data can be processed as we'd like