deposit: removal of the unneeded code

* Removes constructor assignment at fields_group.js

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>
deposit: conferences field typeahead

* Uses data mock.

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>
deposit: trimming identifiers before import

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>