cmd/dist: change fetch to fetch-object command

To allow us to differentiate from fetching an image, fetch a part of an
image and pulling an image, we now call the `fetch` command the
`fetch-object` command. We can now introduce a command that does the
complete image fetch without creating snapshots, allowing `pull` to
perform the entire process.

Signed-off-by: Stephen J Day <stephen.day@docker.com>

cmd/dist/main.go

@@ -61,7 +61,7 @@ distribution tool
 		},
 	}
 	app.Commands = []cli.Command{
-		fetchCommand,
+		fetchObjectCommand,
 		ingestCommand,
 		activeCommand,
 		getCommand,