[FEATURE] Add support for pagination

Problem/Motivation

We want to be able to paginate through results in collections (of entities and relationships). There are several pagination options, this ticket is about page based pagination.

Proposed resolution

1. There is a maximum global page size (per collection type). Stored in the configuration object (defaults to 50 items) and overridable per resource (once we can alter the schema).
2. We will use the page URL parameter. We'll support:
   • page[size] to override the page size (with a max cap by config).
   • page[number] to specify the page number.
   • page[offset] to specify the starting index for the objects to return. page[number] and page[offset] are mutually exclusive, they can't exist in the same request.