Better handling of inline composed schemas in InlineModelResolver

Created by: rienafairefr

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• Filed the PR against the correct branch: master, 3.4.x, 4.0.x. Default: master.

Description of the PR

InlineModelResolver wasn't handling the composedschema case correctly or even at all, with this PR it can transform inline models like this:

ComposedModel:
  allOf:
  - $ref: '#/components/schemas/Model'
  - type: object
    properties:
      prop:
       type: string

into

ComposedModel:
  allOf:
  - $ref: '#/components/schemas/Model'
  - $ref: '#/components/schemas/ComposedModel_allOf'
ComposedModel_allOf:
  type: object
    properties:
      prop:
        type: string

this might help for handling correctly allOf/anyOf/oneOf, even in the case of the presence of inline model