Replace current Movielens scraper with pagination by single request

[kinow]

Instead of several requests to Movielens, use a single one after logged-in: https://movielens.org/api/users/me/movielens-ratings.csv

Example data:

212048 | 10731748 | 652483 | 3.5 | 2.4 | Airplane Mode (2020)
-- | -- | -- | -- | -- | --
212088 | 11388406 | 653601 | 4.5 | 3.19149 | Horse Girl (2020)
212359 | 6156138 | 570735 | 4 | 3.25 | 37 Seconds (2019)
214216 | 10477558 | 610892 | 4 | 3.16667 | Violet Evergarden: Eternity and the Auto Memory Doll (2019)