[rust-server] lacks collectionFormat support

[bjgill]

Description

See swagger-api/swagger-codegen#8173 (comment). I no longer remember what the problem was, but it seems as if we generate invalid Rust when faced with a collectionFormat.

e.g.

      parameters:
        - in: query
          name: color
          type: array
          collectionFormat: csv
          items:
            type: string

(Note: this part of a set of issues from swagger-codegen. I didn't fix this as part of the move to openapi-generator. Thus I strongly suspect rust-server in openapi-generator also suffers the same problem. I'm not planning on working on this at the moment - contributions gratefully welcomed)

openapi-generator version

OpenAPI declaration file content or url

Command line used for generation

Steps to reproduce

Related issues/PRs

Suggest a fix/enhancement

[PiDelport]

This applies to the Rust client, too.