[Feature] Add custom where condition

[amirmasoud]

Add ability to add custom where condition on the QuerySupport file on the runCondition method by overriding or augmenting currently defined conditions.

a suggested syntax could be like:

public function addOperation('_custom_operation', $query, $operation, $field, $value, $exp = 'and')
{
    // return $query->where($field, '=', $value, $exp);
}