[App] Device Connection

The functionality base on the following DeviceScan the valid device when scanning complete will move on to establish the ble connection

#### Rules
1. Device has to be valid (be programmed by ours)
2. Device has to turn on and broadcast BLE single

[App-state]

[ ] AC S1: During ble app-iot device established connection any disconnection occur must be informed and establish device to app reconnection as automated
[ ] AC S2: Device connection state has to be notified (connected, waiting, disconnected,....)
[ ] AC S3: When device has lost connection -> initialize the process of re-scan - re-connection

[App-UI]

[ ] AC UI1: When reconnection state happen notify user via dialog
[ ] AC UI2: When connected state notify and auto closed (timeout in 2s) dialog
[ ] AC UI3: When waiting state notify current is waiting to connect

UI3 -> U2
    \UI1/

GDSC-HSU / gateway