Add filters to the list view

Please note that:
- Some data get filtered by name instead of by code (e.g., the filter on the author checks if the authors field contains the name specified, case-insensitively); other data are filtered by code (e.g. the region). My intention, in fact, is to use text fields for some parameters and dropdown menus for others.
- We are still missing a form (or some helpers to be leveraged) to input the filtering parameters