Remove use of client from CLI setup

[rmweir]

Prior, we were using a kubeconfig client during setup of the platform commands. The client uses the command "vcluster platform token". This would cause an endless loop like the following:

1. you run the "vcluster platform ..." command
2. vcluster makes request to /deployments endpoint, before running the intended command.
3. the k8s client uses vcluster to authenticate the request
4. return to step 2 The request was being made to detect the platform namespace and set it as the default namespace for the backup management command. Now, there is not a default that is set ahead of running the command but if a value was not passed, the CLI will then search for the platform namespace.

What issue type does this pull request address? (keep at least one, remove the others) /kind bugfix

What does this pull request do? Which issues does it resolve? (use resolves #<issue_number> if possible) Fixes ENG-4918

Please provide a short message that should be published in the vcluster release notes Fixed an issue where vcluster would hang during vcluster platform commands.

What else do we need to know?

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