deposit: independent jquery-ui modules

* Loads jQuery UI modules individually

* Removes bundles jquery-ui from deposit module

* Fixes jQuery datepicker module issue

* Removes the global exposed functions

* Refactor the javascript structure

Signed-off-by: Charalampos Tzovanakis <drjova@cern.ch>
assets: drop jquery-ui bundle

* Removes jquery-ui bundle

* NOTE: for now on jquery-ui plugins should be loaded like
  require('ui/{name}')

Signed-off-by: Charalampos Tzovanakis <drjova@cern.ch>