[OK-49577] Add OperationPermissions component

[Drowze]

Description:

Add OperationPermissions component, which should take x-user-permissions OpenAPI extension and render it nicely.

Also did a slight update on the Operation component, to:

• remove permissions from the main extensions object
• render OperationPermissions right below the operation description

---

Demo:

•  "/pet/{petId}": {
     "get": {
       "x-user-permissions": [
         { "name": "view_pets", "details": "Controls access to current user's pets page" },
         { "name": "view_all_pets", "details": "Controls access any user's pets" },
         { "name": "manage_pets" }
       ],
       // ...

  
• // when no x-user-permissions was defined
  
• Notice x-user-permissions is not displayed under extensions (when showExtensions is set to true):