Enable TLS between MariaDB and TrustyAI Service

[sheltoncyril]

Description

Enable and enforce TLS for MariaDB connections.
Add fixture to copy mariadb-ca certificate to trustyai-ca-cert secret.

How Has This Been Tested?

Ran all the tests within TestFairnessMetricsWithDBStorage and verified on the console if the desired state is reached.
Test was run multiple times to check for conflict errors which may indicate dangling resources and none were found, the clean-up works perfectly.

Merge criteria:

• The commits are squashed in a cohesive manner and have meaningful messages.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work

[github-actions]

The following are automatically added/executed:

• PR size label.
• Run pre-commit
• Run tox

Available user actions:

• To mark a PR as WIP, add /wip in a comment. To remove it from the PR comment /wip cancel to the PR.
• To block merging of a PR, add /hold in a comment. To un-block merging of PR comment /hold cancel.
• To mark a PR as approved, add /lgtm in a comment. To remove, add /lgtm cancel.
  lgtm label removed on each new commit push.
• To mark PR as verified comment /verified to the PR, to un-verify comment /verified cancel to the PR.
  verified label removed on each new commit push.

Supported labels

{'/lgtm', '/verified', '/wip', '/hold'}

[sheltoncyril]

/verified