Fix database name extraction from DSN containing a CA file path

[fergusean]

When a DSN contains a path to a CA file for TLS, the database name is improperly extracted.

Sample:

$dsn = 'mongodb://db_admin:secret@abc123.docdb.amazonaws.com:27017/mydb?tls=true&tlsCAFile=/usr/share/pki/ca-trust-source/anchors/aws-rds-bundle.pem&retryWrites=false';
echo $connection->getDefaultDatabaseName($dsn, []);

Before:

aws-rds-bundle.pem

After:

mydb

Checklist

• Add tests and ensure they pass

[GromNaN]

Hello @fergusean, thank you for submitting this PR and contributing to the project.

Could you add a unit test to validate there is no regression?
You can add a case in ConnectionTest::dataConnectionConfig()

[fergusean]

@GromNaN done!