XD-1426 - [UI] Optimize Javascript files

Please note I left third-party Javascript files untouched as they might not be (now or in the future) minification-safe. 

Some files were not using Angular strict DI syntax so they had be to be corrected in order for the application to work. I also configured Angular to work in [`strictDi`](https://docs.angularjs.org/api/ng/function/angular.bootstrap#usage) mode, so that the aforementioned problem can be detected earlier.