Allow duplicate uids in single writeMultiple on InsightEdge w/RocksDB

Use Case:
Loading data from external file to InsightEdge when the grid is configured with RocksDB (MemoryXtend).
Some of the data have same identifier.
Observation:
When the RDD gets saved to the grid, by using saveToGrid, the operation fails on "java.lang.RuntimeException: Duplicate uid in bulk-info.."

The fix is applied in the proxy (GigaSpace) that in case the grid is configured with RocksDB and we are running InsightEdge then to allow such operation by removing duplicates in the client side (proxy).

This behavior can be turned on and off using the space property: space-config.engine.blobstore.rocksdb.allow_duplicate_uids.