First round of changes to support faceting.

Modified the indexers to resolve record subjects and agents (so they
can be indexed).  This led to some changes to endpoints to support the
'resolve' parameter.
WIP add facets to the accession browse list
Add subject filter to the big search; clean up filter partial to only show facets that aren't already active;
Introduce search_result_data object to assist with search data manipulation - required for filters and listing
Accession/lifecycle tests needed to be tweaked to ensure indexer picked up latest changed (suppress/delete namely)
Add the accession's date year to the index to allow for a facet
Fix facets with spaces e.g. subject terms
WIP add sorting of the title field
Add a title_sort field of type String as text could not be sorted correctly
Allow sorting of record type
Allow toggling through the sort directions acs -> desc -> no sort
Add some styles to the header head row
Add some styles to the header head row.. take 2
Add query string as a filter and allow removal as per facets
Remove puts from crud_helper
Add text filter
Fix error when empty filter[] in url
Add a clear all button to the filter
When deleting an Accession, flag this with the listing in case the indexer hasn't yet removed it - if still present the listing will mark it as deleted
Remove .merge and .concat and use .clone instead - also remove 'if' conditionals that weren't required