More spec-compliant handling of unknown fields in REST json

[zah]

No description provided.

[arnetheduck]

this will get noisy with lists - ie a list with 100k blocks during sync will result in 100k warning logs - the fact that an unrecognised field was hit should instead be passed up to the caller that can take appropriate action

[arnetheduck]

lgtm, except that serializers must never log (it's not the right layer for it)

[zah]

I can imagine an API for notifying the caller, but implementing something like this would be a larger development effort. For this hotfix, we can either disable this warning (silently ignoring the fields) or we can assume that these warnings won't be encountered in practice (they can arise only when using the REST API, so the potential excessive output shouldn't be a security concern).

[zah]

I've changed the warning to debug for now and added some TODO comments:
a7f37ce

[arnetheduck]

we can either disable this warning

I would tend towards complete disabling (or trace): we run debug on pretty much all servers and logging in serializers has a tendency to blow up - ie if an attestation gets logged, that's 128 logs per block etc - it's really bad if it happens.

[github-actions]

Unit Test Results

     12 files  ±0     842 suites  ±0   52m 2s ⏱️ + 3m 15s
1 693 tests ±0  1 645 ✔️ ±0    48 💤 ±0  0 ❌ ±0 
9 853 runs  ±0  9 741 ✔️ ±0  112 💤 ±0  0 ❌ ±0 

Results for commit a7f37ce. ± Comparison against base commit 50e8415.