Update CodeMirror to version 5.49.0 (#8381)

* Update CodeMirror to version 5.49.0

* Update CodeMirror versions in librejs and VERSIONS

public/vendor/plugins/codemirror/mode/pegjs/pegjs.js

@@ -1,5 +1,5 @@
 // CodeMirror, copyright (c) by Marijn Haverbeke and others
-// Distributed under an MIT license: http://codemirror.net/LICENSE
+// Distributed under an MIT license: https://codemirror.net/LICENSE
 
 (function(mod) {
   if (typeof exports == "object" && typeof module == "object") // CommonJS