split off the gfl app

the gfl-app-new developed into a one-stop-shop for many tasks regarding the project:

• serving the API to external clients
• trigger tasks for data import via symphony commands
  • data transformation
  • data import to solr
  • data import to S3 (Images; while TEI files are pushed to S3 form the volltexte project pipeline)

this is bad, because a single change on the external API now triggers complete data reimport (25 minutes +), thus the whole setup has become inflexible. the main idea is to split the app for both tasks and to become more flexible. a baby step away from this monolith towards a more modular system.