[Feature Request] Option to add image to the pool (Danbooru)

[megum1n]

It would be great to have an ability to add any image to the pool.

User flow

1. Open post
2. Choose "Add to the pool" option in the menu
3. Pop up window with pool list opens
4. Choose pool from the pop up window
5. Image is added to the pool

Program flow

1. Get pool list /pools.json
2. Append current post ID to the post_ids list of the chosen pool
3. PATCH request to /pools/<pool_id>.json with {"post_ids": [...]} data

"Remove from the pool" option also would be useful. Find and remove <post_id> from the post_ids list. Pop up window should probably display if the current post is already added to the pool.

API docs: https://danbooru.donmai.us/wiki_pages/api%3Apools