Add custom default pagination class

[TimJentzsch]

Relevant issue: Closes #156.

Description:

This changes the default pagination class to a custom one. This allows us to set a page_size parameter to control the number of items per page. The current maximum is set to 500, but we might wanna adjust this to our needs. This change is important for buttercup to reduce the number of API requests and thus the delays.

Checklist:

• [x] Code Quality
• [x] Pep-8
• [ ] Tests (if applicable)
• [x] Success Criteria Met
• [x] Inline Documentation
• [ ] Wiki Documentation (if applicable)