feat: producer avro schema validation

[ccm32004]

Added producer schema validation + tests:

• if message passes schema validation, it processes and sends successfully (happy path)

• if message doesn't pass schema validation and drop is configured, message is reported as successful as to not trigger resends

• if message doesn't pass schema validation and drop is not configured, message is reported as failure downstream to numaflow

Other testing notes:

• tested on pulsar streamnative cluster, registered schema to topic, and then configured the producer pipeline to generate message payloads that were valid/invalid
• added validation for auto produce false and drop being true; resulted in the following log

[KeranYang]

Suggested change

	# When true, drop messages that fail schema/serialization (respond OK, no retry). When false, report failure.
	# When true, drop messages that fail schema/serialization and continue publishing.
	# When false, report failure.

[KeranYang]

Can we implement a validate method for PulsarProducerProperties? useAutoProduceSchema: false, dropInvalidMessages: true is not a validate combination.