Added ability to change document class to be returned in ODM

[ashpumpkin]

issue #11031
Usage:

Robots::find(); //returns Robots
Robots::find(['class' => 'Books']); // you get Books
Robots::find(['class' => 'Phalcon\Mvc\Collection\Document']); // you get Documents
Robots::find(['class' => 'UnknowClass']); // you get php error "Class 'UnknownClass' not found"
Robots::find(['class' => 'KnownClassNotImplementingInterface']); // you get phalcon exception "Object of class 'KnownClassNotImplementingInterface' must be an implementation of Phalcon\Mvc\CollectionInterface or an instance of Phalcon\Mvc\Collection\Document"

In case when exception must be thrown all other check become useless waste of time and that is why class check is made so early.

[andresgutierrez]

Could you please rebase?

[sergeyklay]

@andresgutierrez

[andresgutierrez]

Thanks