XWIKI-10004: Issues with Faceting on Object Properties
* Add script service API to resolve a XClass property reference
* Improve SolrFieldStringEntityReferenceResolver to support resolving relative references.
* Move search facets in separate documents
* Extract the configuration in a separate document.

(cherry picked from commit 4ddc49b5e852be23b5988b0af040979df1ceb70e)

Conflicts:
	xwiki-platform-core/xwiki-platform-search/xwiki-platform-search-solr/xwiki-platform-search-solr-ui/src/main/resources/Main/SolrSearch.xml