deposit: independent jquery-ui modules

* Loads jQuery UI modules individually.

* Removes jQuery UI bundle from deposit module.

* Fixes jQuery datepicker module issue.

* Removes globaly exposed functions and refactors the javascript
  structure.

Signed-off-by: Charalampos Tzovanakis <drjova@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
assets: jquery-ui bundle removal

* NOTE For now on jQuery UI plugins should be loaded using
  `require('ui/{name}')`.

Signed-off-by: Charalampos Tzovanakis <drjova@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>