Allow attributes passed with CSS in libraries (SRI)

Problem/Motivation

Currently independent JS libraries (script loaded via its own SCRIPT tag) have the ability to add custom attributes to the tag and this is not the case for CSS libraries of the same type (scripts loaded via their own LINK tag).

# MODULE.libraries.yml or THEME.libraries.yml
bootstrap.cdn:
  header: true
  remote: https://github.com/twbs/bootstrap
  version: '3.3.6'
  license:
    name: MIT
    url: https://github.com/twbs/bootstrap/blob/master/LICENSE
    gpl-compatible: true
  css:
    component:
      'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css': { type: external, attributes: { integrity: sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7, crossorigin: anonymous }, minified: true }
  js:
    'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js': { type: external, attributes: { integrity: sha384-0mSbJDEHialfmuBBQP6A4Qrprq5OVfW37PRR3j5ELqxss1yVqOtnepnHVP9aJ7xS, crossorigin: anonymous }, minified: true }
  dependencies:
    - core/jquery

This would be helpful when including libraries like Bootstrap:

<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7" crossorigin="anonymous">

<!-- Optional theme -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap-theme.min.css" integrity="sha384-fLW2N01lMqjakBkx3l/M9EahuwpSfeNvV63J5ezn3uZzapT0u7EYsXMjQV+0En5r" crossorigin="anonymous">

<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js" integrity="sha384-0mSbJDEHialfmuBBQP6A4Qrprq5OVfW37PRR3j5ELqxss1yVqOtnepnHVP9aJ7xS" crossorigin="anonymous"></script>

Proposed resolution

Add similar functionality to the CssCollectionRenderer class as implemented by the JsCollectionRenderer class.