Add MTRs to further test coverage around TLS functionality

[tonychen2001]

Description

Increase TLS functionality coverage in MTRs.

A few additional test coverage added:

• Server behaves safely with invalid ssl-cipher configuration
• Server behaves safely when cipher and server certificate are incompatible

Release Notes

N/A

How can this PR be tested?

N/A

Basing the PR against the correct MariaDB version

• [X] This adds test coverage and targets the earliest branch in which the test applies (The added MTRs are applicable to 10.11+).

PR quality check

• [X] I checked the CODING_STANDARDS.md file and my PR conforms to this where appropriate.

Copyright

All new code of the whole pull request, including one or several files that are either new files or modified ones, are contributed under the BSD-new license. I am contributing on behalf of my employer Amazon Web Services, Inc.

[LinuxJedi]

@tonychen2001 I don't have permission to rebase this branch, auto-merge is on, can you please execute a rebase?

[tonychen2001]

@tonychen2001 I don't have permission to rebase this branch, auto-merge is on, can you please execute a rebase?

Hi @LinuxJedi, I've rebased but it disables auto-merge.

[ottok]

@cvicentiu This auto-merge will never pass as the CI is permanently broken in MariaDB..

[vuvova]

what's broken? all checks appear to be successful. AppVeyor isn't part of the branch protection.

[tonychen2001]

I don't know the specifics of the checks but I have observed in the past with the auto-merge feature where, auto-merge has been enabled on the PR but

• Some random check fails for unrelated reasons (e.g. flaky MTR) so the merge is blocked
• After a while, I rebase the branch but this disables auto-merge