title: Case Insensitive String parameter in schema of openApi
body: <p>I have an open API spec with a parameter like this: </p>
  
  <pre><code>- name: platform
    in: query
    description: "Platform of the application"
    required: true
    schema:
      type: string
      enum:
        - "desktop"
        - "online"
  </code></pre>
  
  <p>when I get the "platform" parameter from URL , it can be like this :</p>
  
  <pre><code>platform=online or 
  platform=ONLINE or 
  platform=Online or 
  platform=onLine  or ... any other format
  </code></pre>
  
  <p>but when I am going to use it , it is only valid if the parameter is all lower case like <em>"platform=online"</em>, obviously to match the enum value.</p>
  
  <p>how can I make schema to be the case insensitive and understand all types of passed parameters?</p>