Update tanzu context update tanzu-active-resource to support --clustergroup flag

[anujc25]

What this PR does / why we need it

• Update tanzu context update tanzu-active-resource to support --clustergroup flag
• As part of this change, the context object within the config-ng.yaml file also saves tanzuClusterGroupName under the additionalMetadata section.

      additionalMetadata:
        tanzuClusterGroupName: clustergroupA
        tanzuOrgID: b1d48027-bb69-4a56-a5b8-e941ef29fa4b
        tanzuProjectName: projectA
        tanzuSpaceName: ""

Which issue(s) this PR fixes

Fixes #

Describe testing done for PR

## Set project as active
$ tz context update tanzu-active-resource one-tanzu-demo-1 --project "projectA"
$ tz context list
  NAME              ISACTIVE  TYPE        ENDPOINT                                                                         KUBECONFIGPATH             KUBECONTEXT                 PROJECT   SPACE  CLUSTERGROUP  
  one-tanzu-demo-1  false     tanzu       https://api.tanzu-dev.cloud.vmware.com/org/b1d48027-bb69-4a56-a5b8-e941ef29fa4b  /Users/anujc/.kube/config  tanzu-cli-one-tanzu-demo-1  projectA                       
  tkg-mc-1          true      kubernetes                                                                                   /Users/anujc/.kube/config  kind-mc-1                   n/a       n/a    n/a           

## Set space within a project as active
$ tz context update tanzu-active-resource one-tanzu-demo-1 --project "projectA" --space "spaceA"
$ tz context list
  NAME              ISACTIVE  TYPE        ENDPOINT                                                                         KUBECONFIGPATH             KUBECONTEXT                 PROJECT   SPACE   CLUSTERGROUP  
  one-tanzu-demo-1  false     tanzu       https://api.tanzu-dev.cloud.vmware.com/org/b1d48027-bb69-4a56-a5b8-e941ef29fa4b  /Users/anujc/.kube/config  tanzu-cli-one-tanzu-demo-1  projectA  spaceA                
  tkg-mc-1          true      kubernetes                                                                                   /Users/anujc/.kube/config  kind-mc-1                   n/a       n/a     n/a           

## Set clustergroup within a project as active
$ tz context update tanzu-active-resource one-tanzu-demo-1 --project "projectA" --clustergroup "clustergroupA"
$ tz context list
  NAME              ISACTIVE  TYPE        ENDPOINT                                                                         KUBECONFIGPATH             KUBECONTEXT                 PROJECT   SPACE  CLUSTERGROUP   
  one-tanzu-demo-1  false     tanzu       https://api.tanzu-dev.cloud.vmware.com/org/b1d48027-bb69-4a56-a5b8-e941ef29fa4b  /Users/anujc/.kube/config  tanzu-cli-one-tanzu-demo-1  projectA         clustergroupA  
  tkg-mc-1          true      kubernetes                                                                                   /Users/anujc/.kube/config  kind-mc-1                   n/a       n/a    n/a            

• Incorrect input tests:

## Try to set space and clustergroup both within a project as active
$ tz context update tanzu-active-resource one-tanzu-demo-1 --project "projectA" --space "spaceA"  --clustergroup "clustergroupA"
[x] : either space or clustergroup can be set as active resource. Please provide either --space or --clustergroup option

## Try to set clustergroup without a project
$ tz context update tanzu-active-resource one-tanzu-demo-1 --clustergroup "clustergroupA"
[x] : clustergroup cannot be set without project name. Please provide project name also using --project option

## Try to set space without a project
$ tz context update tanzu-active-resource one-tanzu-demo-1 --space "spaceA"
[x] : space cannot be set without project name. Please provide project name also using --project option

Release note

Support configuring ClusterGroup with the `tanzu context update  tanzu-active-resource` command using `--clustergroup` flag

Additional information

Special notes for your reviewer

[marckhouzam]

I assume any improvement to context list will be done in a separate PR?

LGTM

[anujc25]

I assume any improvement to context list will be done in a separate PR?

LGTM

Correct. UX changes around the tanzu context list will be part of a separate PR.

[prkalle]

lgtm. Thanks for the changes!