Support openapi 3.0 for dynamic configuration

[SkeLLLa]

Seems underlying module swagger-parser already supports new openapi v3 specifications. So I think it would be good if this module will support it as well.

The main idea just to make https://github.com/fastify/fastify-swagger/blob/master/dynamic.js#L59 configurable through options.

However it will also require to refactor some things like securityDefinitions, because in 3.0 they moved to other sections of config file.

I'm not sure that fastify schemas are compatible with openapi v3 specs.

[sjorsjes]

Does this include Bearer auth aswell? https://swagger.io/docs/specification/authentication/bearer-authentication/

[SkeLLLa]

@sjorsjes I've implemented this as separate module https://www.npmjs.com/package/fastify-oas. It's compatible with fastify-swagger and it should support bearer auth.