Implement pagination for multiple batched requests

[ringoldsdev]

Currently only one request is supported. Note that GoogleAnalytics only supports up to 5 concurrent requests.

High level explanation of how it would work.

1. Create requests
2. Run them
3. Before running, identify each request (generate an identifier based on hashed and stringified request without the page token, since it's the only part that changes)
4. Get all the results and append them to the request buffer
5. Check if there's additional data and more pages are needed
6. Add those requests that fit the criteria
7. Run and get results
8. Repeat until no requests can be made
9. Return all results