Refactor robot tests

Start refactoring old robot tests, 

Robot tests were no more use because they failed, they used plone.act.
Now, robot tests passed and use plone.app.robotframework.

All robot tests are no yet mirgated


EDIT:
I also add a b_size field, 
at this time, we can not choose a batch size (number of element visible on one page). We can only limit the number of element in a query.