Disable network switch when device is disconnected

[silva-fj]

When the device is disconnected from the internet, we should disable the network switch to prevent an API error (infinite loop)

• Use https://github.com/react-native-netinfo/react-native-netinfo to detect if the device is connected
• Add a network status banner when the device is disconnected to give feedback to the user. (ask @mikuczi)
• Disable the network switch