Adds a new "icu_collation" field type that exposes lucene's
ICUCollationDocValuesField. ICUCollationDocValuesField is the replacement
for ICUCollationKeyFilter which has been deprecated since Lucene 5.
Transitive dependencies can be confusing and hard to deal with when
conflicts arise between them. This change removes transitive
dependencies from elasticsearch, and forces any dependency conflicts to
be resolved manually, instead of automatically by gradle.
closes#14627
Jim Ferenczi
Matt Weber
Nik Everett
Ryan Ernst