Support OpenAPI 3.1 contentMediaType

[briceruzand]

Hi,

I am using rapidoc with fastapi, since fastapi/fastapi#14953 , it generate OpenAPI 3.1 spec and rapidoc upload form do not work any more.

References :

• Rapidoc : https://rapidocweb.com/examples/file-upload.html#post-/upload-single-file
• OpenAPI : Multipart file uploads: https://learn.openapis.org/upgrading/v3.0-to-v3.1

# OpenAPI 3.0
requestBody:
  content:
    multipart/form-data:
      schema:
       type: object
       properties:
        orderId:
          type: integer
        fileName:
          type: string
          format: binary

# OpenAPI 3.1
requestBody:
  content:
    multipart/form-data:
      schema:
       type: object
       properties:
        orderId:
          type: integer
        fileName:
          type: string
          contentMediaType: application/octet-stream

Thx a lot.