Create QueryPipelineFactory Context Config in maha service at registry level

[pranavbhole]

  "queryPipelineContextFactoryClass": "",
  "queryPipelineContextFactoryConfig": "" 

this config can accept following keys

defaultFactEngine: Engine = OracleEngine,
druidMultiQueryEngineList: Seq[Engine] =DefaultQueryPipelineFactory.druidMultiQueryEngineList.
offHeapRowListConfig