Ability to provide namespace for kubernetes explorer

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(screenshots are often helpful)

### Expected Behavior
In our organization developers has no permissions to list namespaces, so Kubernetes explorer doesn't work.
It would be helpfull if we could provide namespace we want to use.

### Actual Behavior

### Additional Information

- IDE type (e.g. IntelliJ, Pycharm):
- IDE version:
- Cloud Code version (Settings > Plugins > Cloud Code):
- Cloud SDK (Settings > Cloud Code > Cloud SDK)
- Are you allowing the plugin to manage the Cloud SDK:
- Version of the Cloud SDK:
- Skaffold version (If you are using Kubernetes features; Settings > Cloud Code > Kubernetes):
- Operating System:

_Feel free to deviate from this template as needed, especially if you are submitting a feature request._