[BUG] multipleOf-Property not supported by codegens

Created by: SPSpunkt

Description

I have an object that uses multipleOf-Property on numbers (same workaround as described in https://github.com/OAI/OpenAPI-Specification/issues/602), but there seems to be no way to use mustache templates for customization, because the current templating process does not respect the multipleOf-Property in anyway.

openapi-generator version

I used OpenAPI generator v3.3.2 +

OpenAPI declaration file content or url

   amount:
      type: number
      multipleOf: 0.01

Suggest a fix

Making multipleOf-Hook available for templating. (helpful e.g. for creating Custom Constraints/Bean Validation in Java)