Add API to set active UCP resource for UCP context

[prkalle]

What this PR does / why we need it

This PR adds the API to set UCP active resource for the given UCP context.

Changes summary:

• Added API to set active UCP resource for given UCP context. API would call the CLI command to set the active UCP resource for the given UCP context

Which issue(s) this PR fixes

Fixes #

Describe testing done for PR

Unit tests are passed.
Also ran few tests using the below test stub (in ucp.test.go) with ucp context("myucp") already created in CLI.

func TestSetUCPContextActiveResourceSample(t *testing.T) {
        // Test updating the UCP context active resource to space
        os.Setenv("TANZU_BIN", "/Users/pkalle/projects/tanzu-cli/artifacts/darwin/amd64/cli/core/v1.1.0-dev/tanzu-cli-darwin_amd64")
        projectName := "projectA"
        spaceName:="spaceA"
        err := SetUCPContextActiveResource("myucp", projectName, spaceName)
        assert.NoError(t, err)
}

Tested setting the UCP active resource to projectA/SpaceA and validated the context in CLI config file is updated as well as the kubeconfig server URL as shown below

// kubeconfig snippet after update
apiVersion: v1
clusters:
- cluster:
    server: https://ucp-aria.stacks.bluesky.tmc-dev.cloud.vmware.com/org/ee04bfae-a665-4f20-a5b9-d8b043180252/project/projectA/space/spaceA
  name: tanzu-cli-myucp/current


// context snippet after update
      clusterOpts:
        endpoint: https://ucp-aria.stacks.bluesky.tmc-dev.cloud.vmware.com/org/ee04bfae-a665-4f20-a5b9-d8b043180252
        path: /Users/pkalle/.kube/config
        context: tanzu-cli-myucp
      discoverySources: []
      additionalMetadata:
        ucpOrgID: ee04bfae-a665-4f20-a5b9-d8b043180252
        ucpProjectName: projectA
        ucpSpaceName: spaceA

Tested setting the UCP active resource to projectA/spaceB and validated the context in CLI config file is updated as well as the kubeconfig server URL as shown below

// kubeconfig snippet after update
apiVersion: v1
clusters:
- cluster:
    server: https://ucp-aria.stacks.bluesky.tmc-dev.cloud.vmware.com/org/ee04bfae-a665-4f20-a5b9-d8b043180252/project/projectA/space/spaceB
  name: tanzu-cli-myucp/current


// context snippet after update
      clusterOpts:
        endpoint: https://ucp-aria.stacks.bluesky.tmc-dev.cloud.vmware.com/org/ee04bfae-a665-4f20-a5b9-d8b043180252
        path: /Users/pkalle/.kube/config
        context: tanzu-cli-myucp
      discoverySources: []
      additionalMetadata:
        ucpOrgID: ee04bfae-a665-4f20-a5b9-d8b043180252
        ucpProjectName: projectA
        ucpSpaceName: spaceB

Tested setting the UCP active resource to projectA and validated the context in CLI config file is updated as well as the kubeconfig server URL as shown below

// kubeconfig snippet after update
apiVersion: v1
clusters:
- cluster:
    server: https://ucp-aria.stacks.bluesky.tmc-dev.cloud.vmware.com/org/ee04bfae-a665-4f20-a5b9-d8b043180252/project/projectA
  name: tanzu-cli-myucp/current


// context snippet after update
      clusterOpts:
        endpoint: https://ucp-aria.stacks.bluesky.tmc-dev.cloud.vmware.com/org/ee04bfae-a665-4f20-a5b9-d8b043180252
        path: /Users/pkalle/.kube/config
        context: tanzu-cli-myucp
      discoverySources: []
      additionalMetadata:
        ucpOrgID: ee04bfae-a665-4f20-a5b9-d8b043180252
        ucpProjectName: projectA
        ucpSpaceName: ""

Tested setting the UCP active resource to back to Org level and validated the context in CLI config file is updated as well as the kubeconfig server URL as shown below

// kubeconfig snippet after update
apiVersion: v1
clusters:
- cluster:
    server: https://ucp-aria.stacks.bluesky.tmc-dev.cloud.vmware.com/org/ee04bfae-a665-4f20-a5b9-d8b043180252
  name: tanzu-cli-myucp/current


// context snippet after update
     clusterOpts:
        endpoint: https://ucp-aria.stacks.bluesky.tmc-dev.cloud.vmware.com/org/ee04bfae-a665-4f20-a5b9-d8b043180252
        path: /Users/pkalle/.kube/config
        context: tanzu-cli-myucp
      discoverySources: []
      additionalMetadata:
        ucpOrgID: ee04bfae-a665-4f20-a5b9-d8b043180252
        ucpProjectName: ""
        ucpSpaceName: ""

Release note

Add API to set active UCP resource for UCP context

Additional information

Special notes for your reviewer

[vuil]

we should explore possibility of deduping in a followup, but rest of changes lgtm.