mysqli report mode should be per connection instance

[mvorisek]

Description

Currently, the mysqli report mode is per shared driver class mysqli_driver.

related with #12579 (comment) discussion

The motivation for this feature request is safety. Nowdays a lot of code rely on exceptions. And this shared report config is dangerous, as one code may rely on exceptions beiing thrown (as of PHP 8.1 default) and another unrelated code may disable them.

The mysqli_driver class should be completely dropped then.