🔒 Enable SSL listeners for Kafka Brokers

[rmarting]

This PR includes the following use case to resolve #63

[:heavy_check_mark:] Enable SSL listener
[:heavy_check_mark:] Use of server keystore, truststore to expose SSL endpoint
[:heavy_check_mark:] No authentication required
[:heavy_check_mark:] Use of client truststore to connect to the Kafka SSL endpoint
[:heavy_check_mark:] Enable SASL (PLAIN mechanism) authentication under the SSL listener
[:heavy_check_mark:] Enable SASL (SCRAM mechanism) authentication under the SSL listener
[:red_circle:] Enable TLS authentication under the SSL listener

The amq_streams_ssl_no_auth.yml playbook tests and verifies the no authentication use case.
The amq_streams_ssl_auth_sasl.yml playbook tests and verifies the authentication use cases.

The playbooks require the use of a set of keystore and truststore files, all of them created for testing purposes in the folder cerst.

This PR is in Work-in-Progess and it is not ready for review or merge. It is pending of the following actions:

• Review of the molecule tests to use the certificates created. It might require to move to a different place
• Create the molecule test for the new playbooks and verify the execution successfully.

[rmarting]

@rpelisse Could you review the molecule tests to add the new ones created, and the right location for the keystore and truststore files for the molecule tests.

Please, add your commits into this branch as I will need to add more commits to complete the rest of use cases of the issue. Thanks!

[Neustradamus]

@rmarting: Good job about SCRAM!

Linked to:

• State of Play scram-sasl/info#1
• Support for TLS encryption for Kafka Brokers #63
• 🔒 Enable SSL listeners for Kafka Brokers #70
• ✅ Add test for SSL listeners with SASL authentication #73
• 📝 How to enable TLS encryption #74
• 🔐 Enable secured connection from Kafka Connect #76