[MQ] Fix bugs in DigiEventSink device

- The check for consecutive TS indices was still called when receiving Missing TS Data messages even if the bypass flag was set
  => Surround the call with proper if condition
- The range when taking the digis data out of the unpacked timeslice to the DigiEvent was missing the last digi for all detectors
  => Increment the stop iterator to make sure it is included
- In rare case, the device can be pulled down before the Init method is called/finished, which led to a segfault
  => add an InitDone flag + use it to control delete operations in the destructor