Review tasks

• synapse in aleksis/apps/matrix/tests
• SETUP.rst in Docs
• synapse test fixture
• author Jonathan Weth and update email addresses
• default_app_config muss weg
• Copyright updaten
• Slash in URL
• in fixtures/
• matrix.py in util/
• raise from MatrixException from JSONDecodeError
• toggle if in do_matrix_request
• Do parsing before
• dict small everywhere
• raise ValueError if no ID
• Docstrings
• non_polymorphic instead of get_queryset
• matrix imports on top
• debug print
• simply raise
• power_levels with state key
• joined_members testen?
• property/getter system
• Power levels in preferences
• Should the code reduce power levels? → if not, keep current power levels
• provision statt use
• 26. child_spaces zu children
• 27. sync_children → values_list
• 28. User, Device ID, Device Name preference is superflouous
• 29. Help texts for preferences
• [ ]