Add pagination parameters (per_page and page) to get_merge_request_notes

[VovkoO]

Problem

get_merge_request_notes returns a maximum of 20 notes and there is no pagination

Solution

Add pagination parameters (per_page and page). For some reason they are not described in the documentation, but they work.

Testing

node build/index.js --token=xxx --api-url=https://gitlab.example.com/api/v4

[LaserPhaser]

@bbang-dduck @iwakitakuma33 please review.