Service component:

- Renamed DependencyResolver to TaskScheduler
- Enhanced TaskScheduler with an extensible Task API framework and extensible dependency resolver
- Created TaskExecutor providing an extensible task execution environment
- Removed in-memory database; now is stateless and interrogates/updates Context when needed
- Extended gRPC servicer to use new TaskScheduler
- Removed unneeded files and re-organized helper methods
- Extended ServiceHandlerAPI; now SetEndpoint/DeleteEndpoint enables to configure/deconfigure a connection
- Moved ServiceHandlerFactory-related methods to the appropriate file
- Created ConnectionExpander to resolve from ERO-like paths to lists of links
- Created basic tasks: ServiceSetState, ServiceDelete, ConnectionConfigure, ConnectionDeconfigure
- Added skeleton for L2NMEmulatedHandler (to be adapted, now is a copy of L3NM one)