Query result as an indexed array or object by index of choice

I'd love to see such feature.

I think that:

1. By default $primaryKey should be used
   
2. Instead of getResultKey() replacing findAll() we should get a modifier (similar to the asArray())
   

Consider this:

PHP Code:

$model->indexed()->findAll() 


PHP Code:

$model->indexed('id')->findAll()