[wpilibc] Transition C++ classes to units::second_t (#3396)

A lot of these are breaking changes. frc::Timer was replaced with the
contents of frc2::Timer. The others were in-place argument changes or
removing deprecated non-unit overloads.

wpilibcIntegrationTests/src/main/native/cpp/BuiltInAccelerometerTest.cpp

@@ -19,7 +19,7 @@ TEST(BuiltInAccelerometerTest, Accelerometer) {
 
   /* The testbench sometimes shakes a little from a previous test.  Give it
           some time. */
-  Wait(1.0);
+  Wait(1_s);
 
   ASSERT_NEAR(0.0, accelerometer.GetX(), kAccelerationTolerance);
   ASSERT_NEAR(1.0, accelerometer.GetY(), kAccelerationTolerance);