[Feature Request] Add HorovodRun Launch Agent

[Tomcli]

We have many users running the Kubeflow training operator who are also interested in using Wholegraph. For our MPIJobs users, many of them still use HorovodRun as the startup command. Therefore, we want to add HorovodRun as one of the Wholegraph launch agents so our users can use Wholegraph on top of Kubeflow.