add operationId and tag to the generated spec

[ricardobeat]

I was testing out openapi-typescript-codegen which seems like a really good & fast option to create a typescript client, but found a major hurdle.

When generating clients from an OpenAPI spec, it's common to expose a service class with one method per endpoint. Usually you won't be able to create a class method containing the slashes in the request path (ex: api/buyer/get), so generators will use the optional operationId and tags fields to define method names.

For example, in hulk the /api/v1/buyer/create-buyer-branch could be assigned { tags: ["buyer"], operationId: "createBuyerBranch" } so the resulting client looks like:

hulk.buyer.createBuyerBranch({ ... })

Alternatively, an option to use the path itself as operationId in the output json would be enough to generate useful method names. I've opened an issue at ferdikoomen/openapi-typescript-codegen#973 suggesting this as the default behaviour.