Efficient filtering of retrieved cuds objects from backend

[yoavnash]

Currently, to retrieve cuds objects and filter them by using some condition on the data attributes, I use this line of code:

cuds_object = next((c for c in wrapper.session.load_by_oclass(onto.my_oclass) if c.label == 'some_label'), None)

This code does the filtering in code rather than inside the database which is clearly inefficient.

[urbanmatthias]

This is related to #177 isnt it?

[urbanmatthias]

How would you allow the user to do this filtering api wise?