Merge branch 'stable-3.4'

* stable-3.4: (24 commits)
  ParsingQueuePersistenceIT: fix google-common imports
  EiffelEventParser: fix javadoc
  Persist failed tasks
  ParsingQueue: Save failed parsing-tasks
  Keep queued tasks to persist in a Set and not a List
  Correct spelling persistance -> persistence
  ParsingQueue: Move scheduling logic into worker
  Fix EiffelEventParserIt#artcQueued
  Refactor EiffelEventParser and implementations
  EiffelConfig: fix invalid log format
  EventKey: add missing cases to switch/case
  Fix event-name in routing key
  Persist parsing-queue on plugin stop
  EiffelEventParsingQueue: Google-java-format
  Refactor EiffelEventParserIT
  Make EiffelEventParsingQueue#scheduleArtcCreation private
  Extract private method to schedule SCS from submit-event
  Rename EiffelEventParser and EiffelEventParserIf
  Extract interface from EiffelEventParser
  Extract the task description from EventParsingWorker
  ...

Change-Id: I8d6f26aef920b9b7ccd967a5f7f164a02b9c6650