[Analysis] Driver.php (mysqli): remaining findings for baseline

[tyrsson]

Context

Part of #60.

Data

• non-existent-class-like at line 63: a docblock references PhpDb\Mysql\mysqli_result (incorrectly namespaced; should be the global \mysqli_result). Likely a real typo worth fixing on pickup.
• incompatible-parameter-type x2 (createStatement()'s $sqlOrResource, createResult()'s $resource).
• missing-property-type on $options.
• possibly-invalid-argument on Result::initialize() call.
• docblock-type-mismatch on $resource.

These findings will be captured in a mago baseline rather than fixed or suppressed inline.