feat: support Kafka protocol for functions #887

Job	Run time
integration (integration test with downloader, .ci/tests/integration-oauth2/e2e_with_downloader.y...	30m 0s
integration (integration test with oauth2, .ci/tests/integration-oauth2/e2e.yaml)	37m 32s
integration (integration test, .ci/tests/integration/e2e.yaml)	1h 20m 15s
integration (integration test with tls, .ci/tests/integration/e2e_with_tls.yaml)	39m 56s
	3h 7m 43s

Provide feedback