Add End2End Tests

[DanielHabenicht]

a Machine A that would be the test machine
a Machine B that stands in the same network as Machine A and can directly accessed by it
a Machine C that is in a different network and can't be reached by Machine A
a Machine D that is in both networks and runs the proxy
Note: The machines can be containers or full vms. shouldn't matter
Note 2: Machine A should be Windows, Linux and MacOs at the same time