Align 002-api-proposal with current api/v1alpha2 Go Type Definitions

[SinaChavoshi]

The gateway-api-inference-extension/docs/proposals/002-api-proposal/ document is currently outdated and contains discrepancies when compared to the actual Go type definitions in api/v1alpha2/inferencepool_types.go and api/v1alpha2/inferencemodel_types.go.

This misalignment can lead to:

• Confusion for developers implementing based on the proposal.
• Incorrect assumptions in YAML manifests.
• Challenges in developing and running conformance tests that rely on the proposal's specifications. (see API Discrepancy: InferencePoolSpec pod selector field name mismatch between API Proposal 002 and current Go type definition #766)

Action Required:

Update the gateway-api-inference-extension/docs/proposals/002-api-proposal/ document to accurately reflect the API details defined in:

• api/v1alpha2/inferencepool_types.go
• api/v1alpha2/inferencemodel_types.go

This will ensure consistency between the documentation and the codebase, improving clarity and usability for contributors and users.