Add braces to C++ single-line loops and conditionals (NFC) (#2973)

This makes code easier to read and more consistent between C++ and Java.
Also update clang-format settings to always add a line break (even if no braces are used).

wpilibc/src/main/native/cpp/simulation/SPIAccelerometerSim.cpp

@@ -12,7 +12,9 @@
 using namespace frc;
 using namespace frc::sim;
 
-SPIAccelerometerSim::SPIAccelerometerSim(int index) { m_index = index; }
+SPIAccelerometerSim::SPIAccelerometerSim(int index) {
+  m_index = index;
+}
 
 std::unique_ptr<CallbackStore> SPIAccelerometerSim::RegisterActiveCallback(
     NotifyCallback callback, bool initialNotify) {