upload public key 2 microservice (step 2) signed CSR

[kreinhar]

• [ ] make sure the user can upload a public key generated by the user from CLI
• [ ] the UI has to handover the key to the microservice and trigger the start of step 2a
• [x] the agent call the endpoint with the CSR once the privat and public key is created
• [ ] create the CSR and sign the CSR with the private key
• [ ] send the public key and the signed CSR to the microservice