Physics workflows for CTA gRPC Frontend

I'm creating this ticket to better track the work in a TODO-list

• Use gRPC token instead of InsecureChannelCredentials
• CREATE event + test
• CLOSEW (Archive) event + test
• DELETE event + test
• PREPARE (Retrieve) event + test
• ABORT_PREPARE (CancelRetrieve) event + test
• merge the MR on the EOS side