Request body for binary does not resolve properly when using `$ref`

[vishalbd]

This is related to issue #382. This package properly resolves the type of a schema to mode: file when the type is string and the format is binary, but fails to do so if that schema is linked through a $ref. For example,

this works:

requestBody:
  content:
    text/csv:
      schema:
        type: string
        format: binary

but this doesn't:

schemas:
  RequestBody:
    type: string
    format: binary

paths:
  ...
  requestBody:
    content:
      text/csv:
        schema:
          $ref: '#/components/schemas/RequestBody'

In the second example example, the mode of the body is still raw and a random string is generated as an example.

[VShingala]

@vishalbd Thanks for reporting the issue! We'll look into this and update here once we have fix ready for this.

[aakankshabhende]

@VShingala I want to work on this issue. Could you please assign me this?

[VShingala]

@aakankshabhende Sure, I've assigned this to you. Do assign me as reviewer when you raise PR for this.