Add option to SelectQuery condition

I wanted to use a select query condition with OR not always with AND.

This is a temporary improvement and it should have a condition group suggested here but needs more work.

Example usage;

$user_query = new SelectQuery('Account');
$user_query->conditionGlue = ConditionGlue::OR;
$user_query->fields = ['Id'];
$user_query->limit = 1;
$user_query->order['LastModifiedDate'] = 'DESC';
$user_query->addCondition('xxx', [$xxx]);
$user_query->addCondition('yyy', [$yyy]);
$user_query->addCondition('zzz', [$zzz]);
$user_query_response = $this->salesforceClient->query($user_query);