Cluster param is invalid in Openshift Plugin

[ferhoyos]

When Kiali is deployed as Openshift plugin (kiali/openshift-servicemesh-plugin), cluster param in HTTP request used for Multicluster feature is considered invalid:

For example:
api/istio/status?cluster=Kubernetes throws 400 Bad Request. Invalid cluster Kubernetes

This error does not happen when Kiali is used as standalone application within Openshift.

According to https://github.com/openshift/enhancements/blob/master/enhancements/console/dynamic-plugins.md#delivering-plugins, Openshift uses an internal proxy to redirect plugin HTTP requests to corresponding service (in this case Kiali backend service). It seems that cluster param is reserved for internal use within Openshift Console, which validates the cluster name (in a different way that Kiali does).

For example cluster param is used below in internal Openshift API (in this case cluster=local-cluster)

If we use same value cluster=local-cluster for Kiali, the HTTP request is not rejected by Openshift but the cluster is not found in Kiali (Kubernetes is the default cluster name):

For this reason cluster param should be renamed to meshcluster or similar to avoid conflicts with Openshift.