Support ray job

[qile123]

Hello, I hope to take on the work of supporting rayjob in arena. Here is my general design：

Usage example:

arena submit rayjob \
    --name=rayjob-sample \
    --image=rayproject/ray:2.34.0 \
    --head-memory=4Gi \
    --worker-replicas=1  \
    --worker-memory=4Gi \
    --entrypoint="python /home/ray/samples/sample_code.py"

Parameters that need to be specified:

1. the name of ray job.
2. the image of ray job.
3. the command to be executed when submitting rayjob.
4. the cpu resource to HeadPod for the training.(default: 1)
5. the memory resource to HeadPod for the training.(default: 2Gi)
6. the cpu resource to WorkerPod for the training.(default: 1)
7. the memory resource to WorkerPod for the training.(default: 1Gi)