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]]
Sends automated dmails from `Danbooru.config.system_user`, rather than
whichever user is performing the action happens to be (usually User.admins.first).
Also adds a notice in the view that the dmail was automated.
/dmails is restricted to viewing dmails for CurrentUser only (due to
Dmail.visible in the index action). Remove owner_id from subnavbar links
in /dmails, and don't support it in /dmails?search[owner_id], since it
doesn't actually do anything.
Also removes related dead methods and fixes tests that didn't test owner_id properly.
* CurrentUser.dmail_count caused an unnecessary COUNT(*).
* CurrentUser.dmails.unread.present? caused *all* unread dmails to be
loaded. We want to only load the first one.
