IP-Scanner: Sort results by hostname does not work #155

Describe your issue or feature request:
Clicking on "Hostname" in the result list of the IP-Scanner results in a list, that isn't sorted at all. Names are all over the place, and a second click does not reverse that order, or do anything at all.

Steps to reproduce the issue:

1. Open IP-Scanner
2. Scan so that multiple devices are shown
3. Klick on Hostname to see some weird results
4. Klick on Hostname again to see that nothing changed

NETworkManager version:
1.8.1.0

Windows version:
Windows 10 Pro 1803 (Build 17134.345)

.NET-Framework version:
.NET 4.7.2