Create a secure-only Db2 source

[alexandr-shegeda]

Tell us about the problem you're trying to solve

We want to create secure-only versions of connectors that can be used in the Airbyte cloud. The idea is that these connectors inherently prevent certain insecure connections such as connecting to a database over the public internet without encryption.

Describe the solution you’d like

The acceptance criteria for this ticket is:

• Create a new connector source-<name>-strict-encrypt based on the current connector
• modify the connector's spec to hide any options which allow the user to disable TLS
• change the connector to enable TLS by default if the TLS option is not specified
• update connector documentation
• Encrypted connections are tested as part of either a custom integration test or acceptance test. Where possible, test it using a test container. If that's impossible and it must be tested on a real DB instance, create a DB instance in AWS ideally using terraform (but if TF is too hard just create it manually and make a ticket to encode it in TF)
• Create a PR

Implementation hints

This PR contains an example of modifying a DB to only allow using TLS connections.

Note: to perform this task for any given connector, it must first support TLS as described in #5628