[commands] Add idle command (#5555)

wpilibNewCommands/src/main/native/cpp/frc2/command/Commands.cpp

@@ -24,6 +24,10 @@ CommandPtr cmd::None() {
   return InstantCommand().ToPtr();
 }
 
+CommandPtr cmd::Idle() {
+  return Run([] {});
+}
+
 CommandPtr cmd::RunOnce(std::function<void()> action,
                         std::initializer_list<Subsystem*> requirements) {
   return InstantCommand(std::move(action), requirements).ToPtr();

wpilibNewCommands/src/main/native/include/frc2/command/Commands.h

@@ -31,6 +31,14 @@ namespace cmd {
 [[nodiscard]]
 CommandPtr None();
 
+/**
+ * Constructs a command that does nothing until interrupted.
+ *
+ * @return the command
+ */
+[[nodiscard]]
+CommandPtr Idle();
+
 // Action Commands
 
 /**