UI: Add CoInitializeEx to main() startup

Fixes an issue with a certain upcoming as-of-yet-unreleased plugin that
relies on COM

obs/obs-app.cpp

@@ -1660,6 +1660,8 @@ int main(int argc, char *argv[])
 #endif
 
 #ifdef _WIN32
+	CoInitializeEx(0, COINIT_MULTITHREADED);
+
 	load_debug_privilege();
 	base_set_crash_handler(main_crash_handler, nullptr);
 #endif