When running with a remote builder and a local registry:
1. Forward the local registry port to the remote builder
2. Use host networking on the remote builder
3. Use a different builder name as the settings are different

A remote builder can only have one port at a time forwarded, so
concurrent builds on the same registry port will fail.

They were removed for the local registry in favour of the more generic
setup/remove.

Keep the commands for backward compatibility. They can be removed
the next major version.

Restore kamal registry login/logout commands

- Include keepalive options when forwarding port for remote builder
- Log port forwarding errors.

Add local registry support for remote builders

Update registry config documentation to reflect Kamal 2.8.0 changes