Fix UWP : tester and device audio
- Fix UWP tester by using dll packaging instead of robocopy.
- Remove multiple lines in debug logs on UWP.
- Install doc only if requested (This is a workaround to having a path too long on Windows where it is not needed to have docs).
- Export 2 liblinphone_tester functions to allow UWP to use them for fixing dns resolver.
- Fix dns resolver on UWP tester that didn't point to the right IP.
- Wasapi : Add default card only if it exists.
Edited by Julien Wadel