In hermetic test, add additional test cases and move k8sClient object creation so it's called once for all tests

[BenjaminBraunDev]

Adds additional testing for EPP logic for selecting model servers for an inference request. The two new test cases check:

1. If there is no active LoRA for a request for one, the behavior is based solely off queue size and KV-utilization.
2. If there is an active LoRA model but the queue size is above the schedulers threshold value queueingThresholdLoRA than a lower queue size model is chosen despite the higher already having the requested LoRA active to avoid overloading a heavy traffic model.

This also moves the logic for adding test InferenceModel and InferencePool objects into the k8sClient into the BeforeSuit() so it's only called once, otherwise it will error upon trying to create duplicate objects.

Related Issue: #80

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[ahg-g]

/ok-to-test

[ahg-g]

/approve

leaving lgtm to @liu-cong

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ahg-g, BenjaminBraunDev

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[liu-cong]

/lgtm