CYKLO-944: tracking site -> *document relationship using Coral Relation
CYKLO-943: changed 'no limit' cutoff value to 0 days, pass null date to
backend service when selected.
CYKLO-943: fixed a number of errors and annoyances - page number / size
switching and undefined date handling
CYKLO-943, CYKLO-944: implemented filtering documents by site using
structure.SiteDocs relation. This allows efficient calculation of
statistics pers single site with unbounded time period.
CYKLO-943: moved node id set / site set intersection to structure
service
CYKLO-943: pass StructureService reference to ResourceList model base
class.
CYKLO-943: replace SiteFilter that requires node resource retrieval with
initial id set generation before running the category query.
CYKLO-944: intersect the set of documents valid at or after specific
date with set of documents from selected sites
Merge branch 'feature/CYKLO-943' into dev