[App Lab integration] Get on board image version

[MatteoPologruto]

Get the version of the image on the board, to know if it supports user preservation when it is not in EDL mode. The equivalent of adb shell 'cat /etc/buildinfo' could be sufficient, but we want to return only the BUILD_ID.
If /etc/buildinfo does not exist, assume it is a R0 image and return it as the default value.

[lucarin91]

Also, this doesn't feel right to be implemented here in this repo; maybe we should add a functionality in the https://github.com/arduino/arduino-app-cli pkg/board/remote/