Feedback from Demo 19.05.2020

[manuelwedler]

Two small improvements were mentioned:

• In the view for one channel the contact label could be displayed without hovering.
• The address in the header could be displayed in full length.

[manuelwedler]

The address got bigger with this PR #507 . I think we shouldn't show it in full length in the header. The QR code overlay and the tooltip should be sufficient for that.