Merge dagger.io/dagger/engine into dagger.io/dagger

Signed-off-by: Solomon Hykes <solomon@dagger.io>

tests/tasks/scratch/scratch.cue

@@ -1,20 +1,20 @@
 package main
 
 import (
-	"dagger.io/dagger/engine"
+	"dagger.io/dagger"
 )
 
-engine.#Plan & {
+dagger.#Plan & {
 	actions: {
-		image: engine.#Pull & {
+		image: dagger.#Pull & {
 			source: "alpine:3.15.0@sha256:e7d88de73db3d3fd9b2d63aa7f447a10fd0220b7cbf39803c803f2af9ba256b3"
 		}
 
-		exec: engine.#Exec & {
+		exec: dagger.#Exec & {
 			input: image.output
 			mounts: fs: {
 				dest:     "/scratch"
-				contents: engine.#Scratch
+				contents: dagger.#Scratch
 			}
 			workdir: "/"
 			args: [