controller: return solve response through api

Now clients can access the result of the solve, specifically the image
id output. This is a useful refactor, as well as being required if we
want to allow bake to invoke through the controller api.

This also allows us to remove the quiet option from the API, since we
can compute the required progress type outside of the controller, and
can print the image id from the result of the solve.

As a follow-up, we should also be able to remove the image id file
output from the controller api, now that the client has access to it.

Signed-off-by: Justin Chadwell <me@jedevc.com>

monitor/monitor.go

@@ -121,7 +121,7 @@ func RunMonitor(ctx context.Context, curRef string, options controllerapi.BuildO
 							fmt.Println("disconnect error", err)
 						}
 					}
-					ref, err := c.Build(ctx, options, nil, stdout, stderr, progressMode) // TODO: support stdin, hold build ref
+					ref, _, err := c.Build(ctx, options, nil, stdout, stderr, progressMode) // TODO: support stdin, hold build ref
 					if err != nil {
 						fmt.Printf("failed to reload: %v\n", err)
 					} else {