feat: add serialization exceptions to processing logger

[vcrfxia]

Description

Fixes #5364

Two changes in this PR (corresponding to the first two commits):

• add serialization exceptions to the processing log: currently deserialization exceptions are logged but serialization exceptions aren't
• throw a more informative error message in the event that serialization exceptions are caused by UDFs with return types with non-optional schemas, since the error message from Connect (Struct schemas do not match.) isn't particularly actionable by users.

Testing done

Added unit tests. Manual testing underway.

Reviewer checklist

• Ensure docs are updated if necessary. (eg. if a user visible feature is being added or changed).
• Ensure relevant issues are linked (description should include text like "Fixes #")

[agavra]

LGTM! What's the current behavior on error for push queries?

[vcrfxia]

What's the current behavior on error for push queries?

Not sure I understand the question. Push queries use the same serializers and deserializers as persistent queriers so the logging behavior is the same. The name of the logger contains the query ID, which for the push queries is a random large number (in contrast to the sensible query IDs of persistent queries).

If you're asking about the push query behavior for the particular linked issue that this PR fixes, push queries don't generate serialization errors in the examples in the issue since the example push queries don't write to any Kafka topics, so the serializer (where the error is generated) is unused.

[JimGalasyn]

Suggested change

	: The Kafka topic of the record for which deserialization failed.
	: The {{ site.ak }} topic of the record for which deserialization failed.

[JimGalasyn]

Suggested change

	: The Kafka topic to which the ksqlDB row that failed to serialize
	: The {{ site.ak }} topic to which the ksqlDB row that failed to serialize

[JimGalasyn]

LGTM, with a few suggestions.