Simplified deploy/drain timeouts

Remove `stop_wait_time` and `readiness_timeout` from the root config
and remove `deploy_timeout` and `drain_timeout` from the proxy config.

Instead we'll just have `deploy_timeout` and `drain_timeout` in the
root config.

For roles that run the proxy, they are passed to the kamal-proxy deploy
command. Once that returns we can assume the container is ready to
shut down.

For other roles, we'll use the `deploy_timeout` when polling the
container to see if it is ready and the `drain_timeout` when stopping
the container.

test/fixtures/deploy_with_roles.yml

@@ -16,4 +16,4 @@ registry:
   password: pw
 builder:
   arch: amd64
-readiness_timeout: 1
+deploy_timeout: 1