Add the Backstage OpenAPI Catalog Module

[awanlin]

We should add the Backstage OpenAPI Catalog Module. This will generate an API kind for all of the Backstage API that have been generated using OpenAPI. Right now that would include the Catalog, Scaffolder, and Search. This gives adopters a way to better surface the APIs within their Backstage instance to be used by external integrations or teams as needed.

The Backstage OpenAPI Catalog Module is here: https://github.com/backstage/backstage/tree/master/plugins/catalog-backend-module-backstage-openapi