Resolve "Connect QR code scanner and ReposeDataService"

Closes #302 (closed)

For testing you can use this QR code. It was generated using the same tool that is most likely going to be used in production (qrcode for Node): qrcode "{\"repose\":{\"respondent_id\":\"REP-0123\",\"passphrase\":\"ft7e8kje+s\"}}"

Serve the Repose version of the app: ng s @rcc/app -c=repose --ssl

Then click "Scan QR code". After scanning, a modal should pop up offering to save the data. Confirm and the data should be saved to settings.