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).