deposit: fieldlist plugin separation

* Renames fieldlist plugin to dynamicFieldList.

* Moves the plugin to dynamic_field_list.js.

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>
deposit: DynamicFieldList wrapped into a class

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