[feature] persist worker queues to db (#3042)

* persist queued worker tasks to database on shutdown, fill worker queues from database on startup

* ensure the tasks are sorted by creation time before pushing them

* add migration to insert WorkerTask{} into database, add test for worker task persistence

* add test for recovering worker queues from database

* quick tweak

* whoops we ended up with double cleaner job scheduling

* insert each task separately, because bun is throwing some reflection error??

* add specific checking of cancelled worker contexts

* add http request signing to deliveries recovered from database

* add test for outgoing public key ID being correctly set on delivery

* replace select with Queue.PopCtx()

* get rid of loop now we don't use it

* remove field now we don't use it

* ensure that signing func is set

* header values weren't being copied over 🤦

* use ptr for httpclient.Request in delivery

* move worker queue filling to later in server init process

* fix rebase issues

* make logging less shouty

* use slices.Delete() instead of copying / reslicing

* have database return tasks in ascending order instead of sorting them

* add a 1 minute timeout to persisting worker queues

internal/db/bundb/bundb.go

@@ -84,6 +84,7 @@ type DBService struct {
 	db.Timeline
 	db.User
 	db.Tombstone
+	db.WorkerTask
 	db *bun.DB
 }
 
@@ -302,6 +303,9 @@ func NewBunDBService(ctx context.Context, state *state.State) (db.DB, error) {
 			db:    db,
 			state: state,
 		},
+		WorkerTask: &workerTaskDB{
+			db: db,
+		},
 		db: db,
 	}