Add support for MySQL servers that require encrypted connections.

[scottmckenzie]

This PR allows connecting to MySQL servers that require encrypted connections (option require-secure-transport=ON).

To use:

• Set $dbsslca to the full path of a file that contains list of trusted SSL Certificate Authorities.
• Set $dbsslcapath to a directory that contains trusted SSL Certificate Authority certificate files.
• Set $dbsslverifycert to false to disable verification of the server SSL certificate.

[gregdotca]

Thanks for the submission @scottmckenzie!

I definitely want to get this implemented, but I gave it a try today and ran into some issues, so I'll have to take a look when I have a bit more time (I'm currently trying to do some triage and catchup on issues before the end of the week, so that I can better stay on top of things in 2025).

I appreciate the contribution and will eventually merge this, but it will need some tweaking, such as moving the options out of config.inc.php. This file is only used for the app path and DB credentials, and it's not something I ever get users to update manually. With settings like these that the user may need to modify after the initial installation, I generally try to get them into the UI so the user doesn't have to mess around on the actual server.