Feig Notification Parser

Parses following data in following priority order from raw bytes:

1. Data (Tags)
2. Keepalive
3. Generic

Todo

• multiple tags in 1 message
• keepalives
• generics (fallback)
• understand (e.g. temperature alarm) keepalive codes
  • how to test with hw?
• handle feig date format (similar to franke date)
• remove additional Raw field when ready
  • remove also raw keepalive_flags when ready
• add serde serialize to types