Add more waveshare drivers + refactors

[mariusandra]

Few things:

• This adds all waveshare drivers and closes Unknown waveshare driver variant epd2in13[.*] #14
• Only problem: the 4-color 7-color options aren't implemented yet. So all 2- and 3-color options should now work.
• Also Refactors scene and driver generation into their own files
• Starts actually using the background color when at the start of the scene
• Adds exponential retry backoff to the logger