Equatable conformance for ModelConfiguration and ModelConfiguration.Identifier

[Alessan-git]

Summary

This pull request introduces Equatable conformance for the ModelConfiguration and ModelConfiguration.Identifier types.

Changes

• Added extension ModelConfiguration: Equatable (no custom implementation needed).
• Added extension ModelConfiguration.Identifier: Equatable with a custom == operator implementation.

Motivation

This ensures efficient equality checks, improving code readability and maintainability.
Simplifies code such as:

if await newSelectedConfiguration != modelContainer.configuration {
    try await LLMModelFactory.shared.loadContainer(configuration: configuration)
}

[davidkoski]

Good idea, thank you!