[go-server] Support option to generate structs without json field tag

Is your feature request related to a problem? Please describe.

Sometimes there is a necessity to generate models without json field tags. For example when we need models for URI, Query, or Header params that are not in the request body. Additionally we want to use gin's binding validation on these models.

For this scenario we are using the https://github.com/OpenAPITools/openapi-generator/issues/1145 proposal.

The 1145 solution works great. However, as json field tag is automatically generated, it leaves us with models that contain json field tags that are misleading to our API consumers.

Example of generated code:

type GeneratedStruct struct { ID string json:"id" uri:"id" binding:"required,uuid" }

Describe the solution you'd like

We would like to see an option to generate models without json field tags:

type GeneratedStruct struct { ID string uri:"id" binding:"required,uuid" }

Describe alternatives you've considered

From our research it seems our only alternative is to manually remove the json field tag after generation

Additional context

Start by reviewing the go-server generator and the linked issue 1145 proposal to understand how model tags are generated. The completed change should provide an option that omits json field tags while preserving tags such as uri and binding in generated structs.