✨ [WIP] Add OpenAPI v3 schema support to the Virtual Workspace framework

[xmudrii]

Summary

This PR continues work done in #3059.

This PR adds OpenAPI v3 schema support to the Virtual Workspace framework.

The implementation taps into the CreateServingInfo path to generate the OpenAPI v3 spec and adds a handler to the Virtual Workspaces API server for:

• handling the /openapi requests,
• updating the OpenAPI v3 service caches.

Huge thanks to @palnabarun for all the work on this feature so far!

Related issue(s)

Fixes #3242

Release Notes

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