fix elasticsearch connection errors
This MR consists of several elasticsearch connection error fixes:
- Set connection time to live to fix ConnectionClosedException and SocketTimeoutException. Link to the issue with detailed description: #205
- Remove try catch with resources from RestClientTransport, because since ElasticsearchClient is reused now, once underlying RestClientTransport is closed, ElasticsearchClient can't be used anymore and throws CancellationException.
- Make elasticsearch client cache size configurable.
Edited by Mykyta Savchuk