fix: blob were saved directly at shard folder instead of sub folder ``blobs`` if no custom blob path was set
don't use xcontent to set fetchSourceContext/version on SearchContext

this breaks "where _score" as minScore isn't set
anymore on the SearchContext.
build lucene query directly from symbols
support minScore in LuceneQueryBuilder
support type missmatches in EqOperator
use LuceneQueryBuilder also for group by queries
optimize queries using the distance function

using the concrete DistanceFilter implementation should
result in better performance than the generic function
filter.