EZP-23329: hint read-only property
EZP-23329: remove exception from method that needs no implementation
EZP-23329: implement Indexable for ezinteger FieldType
EZP-23329: specify value type for ContentTypeGroupId criterion
EZP-23329: first implementation of Elasticsearch storage
Merge pull request #953 from ezsystems/impl-EZP-22564-elasticsearch-storage

EZP-23329: Implement search SPI on Elasticsearch