- Move code into chatstate module
- Refactor most of the code, make it much simpler

- Remove some unused vars from app

Add method that sequentially works the steps we have to do
before sending first presence

- Move Delimiter into own module
- Move Metacontacts into own module

For subscription requests we dont have a contact obj

Fixes #5294

This lets us now import the app module without setting paths

- init configpaths earlier so logging can access it to store debug logs
- First step for more consistency across Gajim when looking up paths

  Recommended usage for the future:
  app.configpaths.get()
  configpaths.get()

- Add support for Pubsub Avatars
- Dont poll for vCard Updates, only use XEP-0153
- Dont cache vCards
- Store the avatar SHA of roster contacts in the DB
- Store the current SHA of each contact in the Contacts Object
- Move some code into the ConnectionVcard Class

Also added new property 'additional_data' to message event objects. Changes to this attribute (a dict) are passed on from event to event and are also written to the history db as json string (reading of those values isn't implemented yet).