[BUG] Generated request body don't support allOf parameter

[frederikstonge]

Generated request body parameter is now a nullable object (Object?) instead of the actual type.

Example :

"requestBody": {
          "content": {
            "application/json": {
              "schema": {
                "allOf": [
                  {
                    "$ref": "#/components/schemas/Address"
                  }
                ]
              }
            },
            "text/json": {
              "schema": {
                "allOf": [
                  {
                    "$ref": "#/components/schemas/Address"
                  }
                ]
              }
            },
            "application/*+json": {
              "schema": {
                "allOf": [
                  {
                    "$ref": "#/components/schemas/Address"
                  }
                ]
              }
            }
          }
        },