Resolves digitalutsc/islandora_lite_docs#66: Implement a time range filter for federated search

[amym-li]

Changes

New: Year Range Widget

The YearRangeWidget filters through content and returns results within a specified year range. The Solr field and label of the widget can be customized at /admin/config/search/ajax_solr under the Year Range tab. If no Solr field is provided, the widget will be hidden.

Notes:

• If no end year is given or end year is before start year, then the end year is set to the start year

Modified: Current Search Widget

Before Changes:

• The CurrentSearchWidget hides filter queries containing ranges (e.g. [ TO ]). This was originally done to prevent the user from being able to remove preset filter queries (configured under the Conditions tab on the federated search config form), but this causes the year range query to not display under current search.
• When a user clicks 'remove all' to clear their searches, it clears all search fields including the preset filter queries.

After Changes:

• The preset filter queries are passed to the CurrentSearchWidget so that filter queries are hidden only if it matches the preset filter query (instead of a range).
• When a user clicks 'remove all' to clear their searches, it will clear all search fields except for the preset filter queries.