add namespace param for fn and env (#2556)

This PR moves fission CLI as closer as possible to kubectl command behaviour.  We have improved namespace handling behaviour across CLI.

* add namespace param for fn and env
* use common fn for ns check
* update validation
* default namespace for httpTrigger, env and package, config and triggers
* use default ns
* add namespace filter to spec
* add forceNamespace flag
* set current namespace
* add default namespace in config
* add namespace specific destroy
* add all namespace in the list of resources
* add namespace as global tag
* use %s instead of %v
* add test cases for namespace
* use ns in get all functions

.github/workflows/upgrade_test.yaml

@@ -64,6 +64,9 @@ jobs:
           kubectl cluster-info --context kind-kind
           kubectl get nodes
           kubectl get storageclasses.storage.k8s.io
+          kubectl config use-context kind-kind
+          kubectl config set-context --current --namespace=default
+          kubectl config view
 
       - name: Dump system info
         run: |