Enable adding labels in schema

[Gregory-Pereira]

Core feature: Enable specifying other labels in the values schema

Cleanup:

• app version should match minor version
• rename labels to reflect normal k8s labels, ex:

llm-d.ai/inferenceServing: "true" --> llm-d.ai/inference-serving: "true"
llm-d.ai/model: random-model

• remove random-model as a default label

[Gregory-Pereira]

FYI @kalantar, im going to proceed with this to pull into the guides for some QOL updates. I don't expect any objections because its just default labels but if so let me know in post and we can discuss / revert if needed

[zdtsw]

will this be a problem for existing resources? e.g the label is immutable on deployment. the new one inference-serving will be added but the old one infereneServing remains on deployment, then the pod selector wont be able to find pod with inference-serving instead of inferenceServing