Filtering when using ResultSet is case sensitive

[sobiero]

When using ResultSet, filtering is case sensitive. Please make it case in-sensitive like in QueryBulider

on the file /DataTables/Adapters/ResultSet.php lines 37 and 48 please change
$check = (strpos($item->$column, $search) !== false);
to
$check = (stripos($item->$column, $search) !== false);