Support deployment of applications on remote clusters

If an application instance creation request contains an identifier of a remote cluster, the helm commands execution needs to be altered so that deployments are made on remote cluster accordingly.

So all Helm commands related with given app instance/deployment need to be run with additional parameter pointing the a correct kubeconfig file present in the /tmp directory.

Most likely the entities that contain/store information about a given deployment must be enhanced to include additional (optional) parameter which is the custom kubeconfig file path.