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.

lib/kamal/commands/app.rb

@@ -43,7 +43,7 @@ class Kamal::Commands::App < Kamal::Commands::Base
   def stop(version: nil)
     pipe \
       version ? container_id_for_version(version) : current_running_container_id,
-      xargs(config.stop_wait_time ? docker(:stop, "-t", config.stop_wait_time) : docker(:stop))
+      xargs(docker(:stop, *role.stop_args))
   end
 
   def info