Improve enum values for Enum Type in Swagger ReadOnly documentation (#4191)

* Adding enum values for Enum Type in Swagger ReadOnly documentation

* Adding enum values for Enum Type in Swagger ReadOnly documentation (optimisation) and also adding default/example value

* Add new display enums, defaults, and examples when not in TIO mode (another way to have enums values in swagger.json)

* Fix npm test result

* review corrections

* fix: don't render parameter description if field is empty

* use cross-version schema variable to access properties

* pass className through Markdown component usage

* add per-field classNames to Markdown for easier styling + testing

* remove parameter Example field (out-of-scope for this PR)

* get default value from schema instead of top-level parameter

* tests: add e2e cases for swagger2 and oas3

* remove `swagger-petstore-enum.json`

the purpose of this file lives on in the e2e test specs folder

* add missing proptypes validation

* use `classnames` to more effectively union class names

test/e2e/specs/features/parameter-enum-rendering.openapi.yaml

@@ -0,0 +1,21 @@
+openapi: 3.0.0
+info:
+  title: test
+  version: 0.0.0
+paths:
+  /report:
+    get:
+      parameters:
+        - in: query
+          name: rel_date
+          required: true
+          schema:
+            type: string
+            default: today
+            enum:
+              - today
+              - yesterday
+              - lastweek
+      responses:
+        '200':
+          description: OK