Add Swagger Schema Filter Converter

[lucasteles]

By default, StronglyTypedId doesn't play very nicely with Swagger/OpenAPI docs:

• When used on a route the try it out expects an object { Value: TId } which doesn't match with the Json serialize schema

• When used on a returned model, request example and model schema are presented with the full object structure which also doesn't match with the JSON serialized schema

This PR adds an ISchemaFilter implementation option, which makes StronglyTypedId show as expected on SwaggerGen/OpenAPI documentation

Fix #58

[timschwallie]

Very much need this fix.