Fixes an N+1 queries problem in the /moderator/post/queue view by
prefetching disapprovals and uploaders.
Also the way disapproval messages were previously rendered triggered a bunch
of sql queries for each post:
SELECT COUNT(*) FROM "post_disapprovals" WHERE "post_disapprovals"."post_id" = $1 [["post_id", 52]]
SELECT COUNT(*) FROM "post_disapprovals" WHERE "post_disapprovals"."post_id" = $1 AND "post_disapprovals"."reason" = $2 [["post_id", 52], ["reason", "breaks_rules"]]
SELECT COUNT(*) FROM "post_disapprovals" WHERE "post_disapprovals"."post_id" = $1 AND "post_disapprovals"."reason" = $2 [["post_id", 52], ["reason", "poor_quality"]]
SELECT COUNT(*) FROM "post_disapprovals" WHERE "post_disapprovals"."post_id" = $1 AND "post_disapprovals"."reason" IN ('disinterest', 'legacy') [["post_id", 52]]
SELECT COUNT(*) FROM "post_disapprovals" WHERE "post_disapprovals"."post_id" = $1 AND (message is not null and message <> '') [["post_id", 52]]
SELECT "post_disapprovals".* FROM "post_disapprovals" WHERE "post_disapprovals"."post_id" = $1 AND (message is not null and message <> '') [["post_id", 52]]
This refactors to bring it down to one:
SELECT "post_disapprovals".* FROM "post_disapprovals" WHERE "post_disapprovals"."post_id" = $1 [["post_id", 52]]
