[MIE-1608] Added a simple pagination service and implemented it in every endpoint returning lists. 

Pagination Service receives a query object, like: {'offset': 1, 'limit': 50} and a list of items, and return a subset of that list representing the requested page. Default is set to  {'offset': 1, 'limit': 50}

Implemented Pagination Service in every endpoint returning lists. Example: if you go to */api/v1/object/db_user/1/activities* , you can add the query **?limit=20&offset=1** to the URL to filter your results.

Unit tests and bateries provided!
I can do this, but I think by default we should limit the amount of results. Maybe could be better that if you want the total number of results to set it explicitly somehow. What do you think?