Use faster inserts in MySQL (#30820)

* Use faster inserts in MySQL

* Add local_infile check

* PR feedback

* Fix boolean handling for MySQL

* Fix tests; fix MySQL fallback if local_infile is turned off

* Turn local_infile on for MySQL tests

* Another way of doing MySQL local_infile :/

* sanitize-file-name was a misstep. Not needed for security and could cause problems

* Mistaken docstring