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).

wpiutil/src/main/native/cpp/uv/Timer.cpp

@@ -22,7 +22,9 @@ std::shared_ptr<Timer> Timer::Create(Loop& loop) {
 
 void Timer::SingleShot(Loop& loop, Time timeout, std::function<void()> func) {
   auto h = Create(loop);
-  if (!h) return;
+  if (!h) {
+    return;
+  }
   h->timeout.connect([theTimer = h.get(), func]() {
     func();
     theTimer->Close();