[chore] The Big Middleware and API Refactor (tm) (#1250)

* interim commit: start refactoring middlewares into package under router

* another interim commit, this is becoming a big job

* another fucking massive interim commit

* refactor bookmarks to new style

* ambassador, wiz zeze commits you are spoiling uz

* she compiles, we're getting there

* we're just normal men; we're just innocent men

* apiutil

* whoopsie

* i'm glad noone reads commit msgs haha :blob_sweat:

* use that weirdo go-bytesize library for maxMultipartMemory

* fix media module paths

testrig/router.go

@@ -51,7 +51,7 @@ func NewTestRouter(db db.DB) router.Router {
 		}
 	}
 
-	r, err := router.New(context.Background(), db)
+	r, err := router.New(context.Background())
 	if err != nil {
 		panic(err)
 	}