Support OpenAPI V3 tags

[zAlweNy26]

OpenAPI has an interface for the tags key, but I saw there is this not-needed mapping in the generator file:
https://github.com/jlalmes/trpc-openapi/blob/d1eab87f14fc4bf20b000dfc3ecb5fc5b105006b/src/generator/index.ts#L48

I think this package could support both an array of strings (like now) or an array of TagObject (from the openapi-types package).
Or, if we want to introduce a "breaking change", just support the array of objects.
Tell me if my suggestion makes sense to you, I can open a PR to fix that if it's ok.