As a user I would like to set/change the current context

[adietish]

related to #618 (where part of the solution is to be able to switch current project/namespace) related to #630 (where a kube config without a current context can only be corrected by logging into the cluster)

In the current impl on IDEA one cannot switch/set the current context. One can do it in intellij-kubernetes but the noob user is not aware of this, we should offer an explicit option in our plugin.

[adietish]

The implementation for this would slightly change once we use kubernetes-client 7.0.0 which supports multiple config files. We thus decided to postpone this and do it once we bumped to kubernetes-client 7.0.0