CSS optimization settings

[Souptik2001]

• [x] Create three settings fields-
  • dequeue styles handles for non-logged-in users
  • load styles handles async
  • load styles handles async on window events
  • [x] Dequeue the stylesheets provided in settings.
  • [x] Load styles from JS async using loadCSS. Some on window events and some automatically on page load.
  • [ ] Add a settings field to take the classes which should be present in the DOM and in that case only the styles should be loaded.
• [x] Create a checkbox to include amp-boilerplate CSS( used to avoid CLS issue ).
• [x] Create a checkbox to disable all CSS concatenation on VIP GO platform.
• [x] Create a field to provide handles of CSS for which only concatenation is to be skipped.( will have no effect if the above option is checked ).