[Core] Improves ModuleConfigLoader and core.pagination.js

* ModuleConfigLoader: Built-in config handler now allows for dot.Notation keys, which are
                      autimatically converted to multidimensional arrays.

* core.pagination.js: Adds support for a loading indicator. Any element with the class .pagination-loading within the
                      .pagintation-container is displayed upon reloading.
[Applications] Fixes: Dashboard applications list does not work.

* Adds router.routes.config.php: Outsourcing of router config.

(references #4918, gh-20)