Data Manager: SparqlStream extends Transform

DriverSparqlStream now more correctly extends stream.Transform instead
of stream.Writable.
Data manager: extensive refactoring
Data Manager: Refactoring
Data Manager: Reinit streams etc.

* Streams are cleared at the end of a flush
* Driver instances which have been removed are cleared from
instanceObjects and instanceLogs (to support metadrivers)
Data manager: Remove listDrivers and viewDriver
Data manager: Fetch all instances of a driver
Data Manager: Prevent double fetching
Data Manager: header layout
Add dependency for driver-meta-datagoid
Bar charts text fix