Update how the microcontroller handles sudden Bluetooth disconnection

As far as I am aware of, there are no in-built functions that can be used to check if the Bluetooth module has established a successful connection with the app. As a result, the microcontroller has no idea if the app is connected or not.

However, the app knows if a successful connection has been established. So, a work around has been developed which solves this issue.

When a successful connection has been made, the app sends the device a message informing it a connection has been established. This was, the microcontroller knows that is connected to the app.

Now if the app suddenly disconnects from the device, app will of course know but the device wont. On top of this, the app can no longer send a message to the device informing the microcontroller on the connection status.

This needs to be fixed by using in-built commands. A good starting point is to research AT-commands or other Bluetooth modules.

Start by reviewing the existing C++ microcontroller and Bluetooth handling, then research the Bluetooth module's AT commands or other built-in connection-status commands. Done means the device can detect a sudden app disconnection without relying on a follow-up message from the app and can update its connection state accordingly.

Written by the indexing model from the issue text.