fix(oas3): add support for oneOf/anyOf JSON Schema keywords in request-body rendering (#9767)

Refs #9763

test/e2e-cypress/e2e/features/plugins/oas3/one-of-any-of-example.cy.js

@@ -11,7 +11,7 @@ describe("OpenAPI 3.0 oneOf and anyOf example", () => {
           .get(".try-out__btn")
           .click()
           .get("textarea")
-          .contains("documentDate")
+          .contains("NestedSchemaExample.pdf")
           .should("exist")
         cy.contains("/documentsWithCombineOneOf").click()
         cy.contains("/documentsWithCombineAnyOf")
@@ -20,7 +20,7 @@ describe("OpenAPI 3.0 oneOf and anyOf example", () => {
           .contains("Try it out")
           .click()
           .get("textarea")
-          .contains("documentDate")
+          .contains("ParentSchemaExample.pdf")
           .should("exist")
       }
     )

test/e2e-cypress/static/documents/features/oas3-one-of-any-of-example.yaml

@@ -51,7 +51,7 @@ components:
           type: string
           default: ''
           maxLength: 64
-          example: MyDocument.pdf'
+          example: NestedSchemaExample.pdf'
         category:
           type: string
           pattern: ''
@@ -172,6 +172,15 @@ components:
         - $ref: '#/components/schemas/ModelPostDocumentPolicy'
         - $ref: '#/components/schemas/ModelPostDocumentCustomer'
         - $ref: '#/components/schemas/ModelPostDocumentInvoice'
+      example:
+        title: ParentSchemaExample.pdf
+        category: Policy
+        type: Policy
+        issuingApplicationId: App1
+        documentDate: '2021-01-01'
+        sharedWith:
+          - CustomerPortal
+        policyNumber: '132456'
     ModelPostDocumentAnyOfCombineModelFile:
       allOf:
         - $ref: '#/components/schemas/ModelFile'