feat: makes mutual TLS optional for postgres, mysql/mariadb and grpc

[NickUfer]

This PR makes it possible to create a secure connection to a postgresql, mariadb/mysql or grpc server without the requirement of a client certificate. Mutual TLS would be optional.

[iegomez]

@NickUfer thanks for this new PR!

I see you added new commits a couple of hours ago, so I believe it's still a WIP. Also, could you throw in some tests for the changes? Let me know when it's ready for review.

Cheers!

[NickUfer]

In the latest commits I added basic support for tls and mutual tls tests and in the coming days I will add the actual tests for both tls and mutual tls :+1:

[iegomez]

That's awesome, thank you very much!

[NickUfer]

That's awesome, thank you very much!

Thank you and the other contributors for creating this project in the first place. It will be pretty valuable to me 😄

I think the PR is ready for review 👍🏼 Tests should run through. In the process I found some problems with the tls implementation in pgsql and grpc, these problems should be fixed too.

[iegomez]

@NickUfer sorry for the late reply, I've been a bit busy and missed your comment. I'll take a new look during the week.

[iegomez]

@NickUfer the code scan caught some leaks that need to be addressed. Other than that, could you target release-2.0.0 so @maab may then rebase their PR and merge as well? Afterwards I'll merge that into master and make a release.

[NickUfer]

@iegomez everything is ready now after some delays...got sick sadly

[iegomez]

Thanks, @NickUfer!

I need to run an errand now, I'll merge and release when I get back.

[maab]

Thank you very much @NickUfer and @iegomez for the work you had with reviewing and integrating this great PR!