Remove unneeded and falsy String.trim polyfill (#5066)

1. [it is not required anymore since ages](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/Trim#Browser_compatibility)
2. If "this" is of type type "object", an instance of the same type is returned. [This is completely wrong, because it should be "string"](https://tc39.es/ecma262/#sec-string.prototype.trim), which causes things like [sorting in BootstrapVue tables to break](https://github.com/jenkinsci/dependency-track-plugin/blob/cc5f1bb8900f201384f05b633471dbd7ca48c69a/src/main/webapp/js/result-action.js#L6).

war/src/main/webapp/scripts/hudson-behavior.js

@@ -2775,20 +2775,6 @@ var toggleCheckboxes = function(toggle) {
     }
 };
 
-// this used to be in prototype.js but it must have been removed somewhere between 1.4.0 to 1.5.1
-String.prototype.trim = function() {
-    var temp = this;
-    var obj = /^(\s*)([\W\w]*)(\b\s*$)/;
-    if (obj.test(temp))
-        temp = temp.replace(obj, '$2');
-    obj = /  /g;
-    while (temp.match(obj))
-        temp = temp.replace(obj, " ");
-    return temp;
-}
-
-
-
 var hoverNotification = (function() {
     var msgBox;
     var body;