[commands] Remove deprecated classes and functions (#5409)

Removes:
- PerpetualCommand
- Command.perpetually()
- CommandGroupBase
- Command.IsGrouped() (C++ only)
- Command.SetGrouped() (C++ only)
- Command.withInterrupt()
- ProxyScheduleCommand
- Button
- InternalButton, JoystickButton, NetworkButton and POVButton now subclass Trigger
- Old style Trigger functions:
    - Trigger.whenActive
    - Trigger.whileActiveOnce
    - Trigger.whileActiveContinuous
    - Trigger.whenInactive
    - Trigger.toggleWhenActive
    - Trigger.cancelWhenActive
- CommandScheduler.clearButtons()
- CommandScheduler.addButtons() (Java only)
- Command supplier constructor of SelectCommand

wpilibNewCommands/src/test/native/cpp/frc2/command/CommandDecoratorTest.cpp

@@ -9,7 +9,6 @@
 #include "frc2/command/FunctionalCommand.h"
 #include "frc2/command/InstantCommand.h"
 #include "frc2/command/ParallelRaceGroup.h"
-#include "frc2/command/PerpetualCommand.h"
 #include "frc2/command/RunCommand.h"
 #include "frc2/command/SequentialCommandGroup.h"
 
@@ -122,21 +121,6 @@ TEST_F(CommandDecoratorTest, AndThen) {
   EXPECT_TRUE(finished);
 }
 
-TEST_F(CommandDecoratorTest, Perpetually) {
-  CommandScheduler scheduler = GetScheduler();
-
-  WPI_IGNORE_DEPRECATED
-  auto command = InstantCommand([] {}, {}).Perpetually();
-  WPI_UNIGNORE_DEPRECATED
-
-  scheduler.Schedule(&command);
-
-  scheduler.Run();
-  scheduler.Run();
-
-  EXPECT_TRUE(scheduler.IsScheduled(&command));
-}
-
 TEST_F(CommandDecoratorTest, Unless) {
   CommandScheduler scheduler = GetScheduler();
 

wpilibNewCommands/src/test/native/cpp/frc2/command/CommandRequirementsTest.cpp

@@ -12,7 +12,6 @@
 #include "frc2/command/ParallelCommandGroup.h"
 #include "frc2/command/ParallelDeadlineGroup.h"
 #include "frc2/command/ParallelRaceGroup.h"
-#include "frc2/command/SelectCommand.h"
 #include "frc2/command/SequentialCommandGroup.h"
 
 using namespace frc2;

wpilibNewCommands/src/test/native/cpp/frc2/command/ConditionalCommandTest.cpp

@@ -6,7 +6,6 @@
 #include "frc2/command/Commands.h"
 #include "frc2/command/ConditionalCommand.h"
 #include "frc2/command/InstantCommand.h"
-#include "frc2/command/SelectCommand.h"
 
 using namespace frc2;
 class ConditionalCommandTest : public CommandTestBase {};

wpilibNewCommands/src/test/native/cpp/frc2/command/PerpetualCommandTest.cpp

@@ -1,25 +0,0 @@
-// Copyright (c) FIRST and other WPILib contributors.
-// Open Source Software; you can modify and/or share it under the terms of
-// the WPILib BSD license file in the root directory of this project.
-
-#include "CommandTestBase.h"
-#include "frc2/command/InstantCommand.h"
-#include "frc2/command/PerpetualCommand.h"
-
-using namespace frc2;
-class PerpetualCommandTest : public CommandTestBase {};
-
-TEST_F(PerpetualCommandTest, PerpetualCommandSchedule) {
-  CommandScheduler scheduler = GetScheduler();
-
-  bool check = false;
-
-  WPI_IGNORE_DEPRECATED
-  PerpetualCommand command{InstantCommand([&check] { check = true; }, {})};
-  WPI_UNIGNORE_DEPRECATED
-
-  scheduler.Schedule(&command);
-  scheduler.Run();
-  EXPECT_TRUE(scheduler.IsScheduled(&command));
-  EXPECT_TRUE(check);
-}

wpilibNewCommands/src/test/native/cpp/frc2/command/button/TriggerTest.cpp

@@ -3,7 +3,6 @@
 // the WPILib BSD license file in the root directory of this project.
 
 #include <frc/simulation/SimHooks.h>
-#include <wpi/deprecated.h>
 
 #include "../CommandTestBase.h"
 #include "frc2/command/CommandPtr.h"
@@ -207,24 +206,6 @@ TEST_F(TriggerTest, Negate) {
   EXPECT_TRUE(scheduler.IsScheduled(&command));
 }
 
-// this type of binding is deprecated and identical to OnTrue
-WPI_IGNORE_DEPRECATED
-TEST_F(TriggerTest, RValueTrigger) {
-  auto& scheduler = CommandScheduler::GetInstance();
-  int counter = 0;
-  bool pressed = false;
-
-  RunCommand command([&counter] { counter++; }, {});
-
-  Trigger([&pressed] { return pressed; }).WhenActive(std::move(command));
-  scheduler.Run();
-  EXPECT_EQ(counter, 0);
-  pressed = true;
-  scheduler.Run();
-  EXPECT_EQ(counter, 1);
-}
-WPI_UNIGNORE_DEPRECATED
-
 TEST_F(TriggerTest, Debounce) {
   auto& scheduler = CommandScheduler::GetInstance();
   bool pressed = false;