Manually merge 3.0.x into master

Make table and column comments non-nullable strings

Dropped support of fetching objects and non-zero column

1. `FetchMode::STANDARD_OBJECT` and `FetchMode::CUSTOM_OBJECT` are no longer supported.
2. `FetchMode::COLUMN` with a non-zero index is no longer supported.
3. Incompatible change in the `Connection::fetchColumn()` signature where the 3rd argument is now `$types`, not `$columnIndex`.

Upgrade PHPUnit to 9.1

Do not require hostname for non-persistent MySQL connection and require for persistent

Enable PHPStan strict rules

Fix parsing column comments on SQLite

Reworked type-based and conditions and clarified some types to justify the ones that remain unchanged.

Removed the hard-coded MySQL default port and the usage of ini-settings

Removed EchoSQLLogger