deposit: dynamic list macro addition
- Creates Jinja macro for "Add more" button to be able to personalize it in different installations.
- Adds new file ext.template.utils with helper function to render macros from a template.
Signed-off-by: Javier Martin Montull <javier.martin.montull@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>