PerSystDB: adding job cache to avoid querying mysql job ids. executeOnStart and executeOnStop are now used in the PerSystSqlOperator.

In case sql connection is gone (error 2006), we finalize the connection to avoid memory leaks in mariadb lib.

-CollectAgent and Pusher adapted for special handling of event data
-Handful of other fixes and improvements

-add implementation for calieventdatastore
-requires adaption of CA, Pusher to actually store data in it

-CED should go into separate table
-adds header files for required libdcdb extension
-add other sideshow stuff required for new Cassandra table
-actual implementation outstanding

1. Check for nullptr if metadata is set. 2. Changing scaling_factor to be multiplied instead of divided (dcdb nomenclature).

-can send event data from cali service to pusher plugin
-refactored sample data symbol lookup: is now done by cali service
-cali service only sends timestamp and data-string to pusher plugin
-outstanding TODO: push event data into separate Cassandra table

Removing puning of ints to doubles and viceversa, and implementing use of scaling factor from metadata

- Especially useful in Collect Agent: now there is no need to restart
the CA to instantiate operator plugins after sensors have been
published