Implement all available device commands on backend

[choden-dev]

Overview

The commands that relate to setting configuration on the device have been implemented. This includes:

• Clearing all images
• Set an image for a specific zone
• Configuring a list of actions for an input (introduced in Implement backend socket interface #7)
• Setting brightness
• Setting the boot logo
• Clearing a specific image

Top level message

Protobuf doesn't support handling different messages when parsing, so the workaround was to introduce a TopLevel message that the client sends and make use of the oneof type to make sure we get a mutually exclusive message

To do

The following will be added in a following PR to reduce scope:

• Sending commands from server to a client
• DB operations for smaller commands
  • Clearing images (need to remove from DB)
  • Brightness
  • Boot logo
  • These should also be read on startup

Note

Unrelated but we would also have to work on a new state for when the device is disconnected (i.e scan for device again).