[MTB] implement benchmark lifecycle

[phoenixking25]

Task to run preliminary tests/checks before running benchmarks.

• Check the given namespace is valid or not.
• Check the given user/SA is valid or not.
• Check if there is KubeConfig at $HOME/.kube/config (alternative take kubeconfig from ENV.
• Check the given user has RBAC privileges to create pods/services/deployments.

[JimBugwadia]

@phoenixking25 - please rename to "implement benchmark lifecycle" or close and open a separate issue. As discussed we can add a common validate function (may be different per level) and then for each benchmark define the lifecycle phases:

• validate or Pre-Run: if this returns an error the test is marked as "error" instead of "fail".
• Run: if this returns an error the test is marked as "fail", otherwise "pass".

Not sure if we need a post-run. Thoughts?