Collections: filter dates require full ISO strings

When calling out the Collections REST API, we can filter queries by date with created_before, created_after, updated_before, updated_after.

These dates should be any partial ISO 8601 strings, which round to the earliest/latest resolution. So basically if I say created_before=2024-12-08 It'll return anything created before the start of the 8th of December

Per the spec:

updated_after / created_after only returns records GTE this the start of (last second? of) this date
updated_before / created_before only returns records LTE the end of (last second? of) this date

Note: uh is that spec inverted? Anything created before 8th december should not be include. If doing created after, then also anything created on dec 8 should be excluded. I suppose you could also do created_at which includes anything inside that interval - so created_at=2024-12-08 should return anything created on the 8th december.

Anyway, I can simulate this behaviour in the adaptor, but the backing API should really be providing this behaviour

Reproduction

This returns a 400 bad request

curl -X GET http://localhost:4000/collections/stuff?updated_after=2024-12-06 -H "Authorization: Bearer $OPENFN_PAT"

But this is fine:

 curl -X GET http://localhost:4000/collections/stuff?updated_after=2024-12-06T12:00:12.177825Z -H "Authorization: Bearer $OPENFN_PAT"

Start at the Collections REST API date-filter handling and reproduce the issue with the provided curl commands. Review issue 2566 for the intended boundary semantics; done means partial ISO 8601 dates are accepted for the date query parameters with documented, tested start/end-of-day behavior.