Support the proper meadow.config.yaml bits for cell

[ctacke]

With WiFi you have these options (and I wonder if they maybe should be in something other than "Coprocessor" now)

#Coprocessor:
  # Should the ESP32 automatically attempt to connect to an access point at startup?
  # If set to true, wifi.config.yaml credentials must be stored in the device.
#  AutomaticallyStartNetwork: true

  # Should the ESP32 automatically reconnect to the configured access point?
#  AutomaticallyReconnect: true

  # Maximum number of retry attempts for connections etc. before an error code is returned.
#  MaximumRetryCount: 7

These should probably be available to Cell adapters, too