[KIP-932] Add SASL testing pipeline on CI and share consumer tests for SASL/OAUTHBEARER

[Ankith L (Ankith-Confluent)]

• Add share consumer SASL/OAUTHBEARER tests across 0022, 0126, 0128, and 0142
• Add rd_kafka_share_sasl_background_callbacks_enable() public API
• Add Semaphore CI pipeline for SASL testing (PLAIN, SCRAM, GSSAPI, OAUTHBEARER)

[confluent-cla-assistant]

🎉 All Contributor License Agreements have been signed. Ready to merge.
_{Please push an empty commit if you would like to re-run the checks to verify CLA status for all contributors.}