Refactoring TLS 1.3 support

[SebaLukas]

Describe your changes

Refactoring connection_ssl:

• Updating TLS1.3 support
• Setting on runtime the verify mode based on tls version
• Generating the vehicle cert leaf hash for pause/resume
• Refactoring the tls_keylog callback
• Adding a standalone connection_openssl test / standalone tls server to test the server, generating own certs for this tls server and openssl client

Issue ticket number and link

A prober tls 1.3 support is missing. This PR changes that. For Pause/Resume a prober TLS 1.3 support is necessary.

Checklist before requesting a review

• I have performed a self-review of my code
• I have made corresponding changes to the documentation
• I read the contribution documentation and made sure that my changes meet its requirements

[AssemblyJohn]

Only one note that I'd have on this PR. I know it will be quite complicated, but is there any way that we can have this test somehow introduced in the unit tests (and as a result introduced in the CI)?

From my experience with other conn/servers even if some integration tests do not test everything it would be a huge help when further modifying this class.

The integration test could do something simple, as to open 2 child processes, or to run a script (std::system) or something along those lines.