Initial commit of cross connect integration test project (#3434)

Adding as a separate project so current integration tests stay working.

crossConnIntegrationTests/src/main/native/dt/Main.cpp

@@ -0,0 +1,5 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+int main() {}