Update blueapi calls to use the api set up on the cluster

[noemifrisina]

Now that both the I24 app and blueapi are deployed on the cluster, we should correctly set up things so that they can communicate without running into CORS errors. TO do this we need to:

• in the i24-daq-ui helm chart inside i24-services add under upstreams

- id: blueapi
  path: /api/
  rewriteTarget: /
  uri: http://i24-blueapi.i24-beamline.svc.cluster.local

• replace the use of the BLUEAPI_SOCKET with just /api/