Remove implementation of moment.js

[renato-b]

The UI library comes with an embedded implementation of moment.js (tradeshift-ui/src/third-party/moment-with-locale.js) which is available at ts.ui.moment.
This is not really optimal as the moment library can be included independently in the package.json file if needed. Moreover if independently used it can be upgraded easily to the latest version.

Hint: Jacob and Nima have developed a tool to search for patters in our GIT repository; it can be used to see if any front-end app refers to the string ts.ui.moment.