[Feature] Filter Duplicate Boosts

[sneakers-the-rat]

https://wiki.neuromatch.social/Filter_Duplicate_Boosts

It's annoying to see the same boost in the local TL all the time. This PR filters public feeds so only the most recent boost of a post is displayed.

It modifies the SQL query s.t. it looks like this:

SELECT "statuses"."id",
       "statuses"."updated_at"
FROM "statuses"
INNER JOIN "accounts" ON "accounts"."id" = "statuses"."account_id"
WHERE "statuses"."visibility" = $1
  AND "accounts"."suspended_at" IS NULL
  AND "accounts"."silenced_at" IS NULL
  AND (statuses.reply = FALSE
       OR statuses.in_reply_to_account_id = statuses.account_id)
  AND ("statuses"."reblog_of_id" IS NULL
       OR "statuses"."id" =
         (SELECT MAX(id)
          FROM statuses s2
          WHERE s2.reblog_of_id = statuses.reblog_of_id))
  AND ("statuses"."local" = $2
       OR "statuses"."uri" IS NULL)
  AND "statuses"."deleted_at" IS NULL
  AND 1=1
  AND "statuses"."id" < 111813463418866657
ORDER BY "statuses"."id" DESC LIMIT $3 [["visibility", 0], ["local", true], ["LIMIT", 20]]

So the feed selects statuses that are either a) not boosts (reblog_of_id IS NULL), or b) are a boost that has the maximum ID for all posts with a matching reblog_of_id column

Before merging:

• need to also take the pagination parameters from the get call and pass them to the without_duplicate_reblogs scope, because otherwise we will be querying all boosts and statuses every time.
• tests!