Support for WinGDK

[bruno-garcia]

Received from a customer:

WinGDK support for Game Pass/Xbox app on windows. As far as I know this only requires some minor modifications to how the plugin is built - namely that it switches to breakpad instead of crashpad when making a WinGDK build. We've hacked this in ourselves by having a second sentry library in our source tree linked against breakpad and by modifying the sentry build.cs a bit, but would be good for proper support so we don't have to maintain our own modifications.