Improve and generalize {fmt} formatters

[dominiklohmann]

📔 Description

See logger_formatters.hpp:

• We now have fallback formatters based on printable and the stringification inspector.
• id_or_name is now applied automatically.
• Some log messages had their formatting corrected.
• render is now automatically called on errors.
• <unprintable> is no more.

📝 Checklist

• All user-facing changes have changelog entries.
• The changes are reflected on docs.tenzir.com/vast, if necessary.
• The PR description contains instructions for the reviewer, if necessary.

🎯 Review Instructions

File-by-file.

[lava]

I admittedly only sampled the diff, but what I've seen looks reasonable, and with a PR this size I think its more efficient to merge now and maybe follow-up on issues that we overlooked, rather than extending the lifetime of this PR.