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).

wpilibOldCommands/src/main/native/cpp/commands/InstantCommand.cpp

@@ -39,4 +39,6 @@ void InstantCommand::_Initialize() {
   }
 }
 
-bool InstantCommand::IsFinished() { return true; }
+bool InstantCommand::IsFinished() {
+  return true;
+}