Issue 5760 - Use relative require paths

qunit/tests/cssEscaping.js

 "use strict";
 
 {
-  const {Filter, ElemHideFilter} = require("filterClasses");
-  const {escapeCSS, quoteCSS} = require("filterComposer");
+  const {Filter, ElemHideFilter} =
+    require("../../adblockpluscore/lib/filterClasses");
+  const {escapeCSS, quoteCSS} = require("../../lib/filterComposer");
 
   QUnit.module("CSS escaping");
 
   test("CSS escaping", () =>
   {
     function testSelector(opts)
     {
       let mustMatch = opts.mustMatch !== false;
       let doc = document.implementation.createHTMLDocument();
 
@@ skipping 76 matching lines @@
 
       // Leading dashes must be escaped, when followed by certain characters.
       testEscape("-" + chr);
     }
 
     // Test some non-ASCII characters. However, those shouldn't
     // require escaping.
     testEscape("\uD83D\uDE3B\u2665\u00E4");
   });
 }