Fix Comparison::CONTAINS to check is_string before str_compare

[cage-is]

In Comparison there is a line that says

self::Contains => str_contains($subject, $reference), /* @phpstan-ignore-line */

Since this is checking $subject with str_contains it should check first if it is a string. This seems to have been handled in other various comparisons already (e.g. self::Regexp => is_string($subject) && 1 === preg_match($reference, $subject), /* @phpstan-ignore-line */)

TypeError: str_contains(): Argument #1 ($haystack) must be of type string, null given
/var/www/src/Query/Constraint/Comparison.php:102
/var/www/src/Query/Constraint/Column.php:78
/var/www/src/Query/Constraint/Criteria.php:47
/var/www/src/Query/Constraint/Criteria.php:108
/var/www/src/ResultSet.php:395
/var/www/src/StatementTest.php:260

[nyamsprod]

thanks for the bugfix and the nice catch! I will merge your contribution 👍🏾

[nyamsprod]

I have updated your test case the assertSame was not mandatory an assertCount is enough as the ResultSet implements the Countable interface which means that iteration is done which highlights your fix 😉