[robotpy][examples] Split examples and snippets (#8944)

This also updates the bazel scripts to behave more like the C++ and Java
examples, and updates the copybara scripts to be able to sync up
`mostrobotpy`

robotpyExamples/examples/UnitTest/constants.py

@@ -0,0 +1,16 @@
+#
+# 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.
+#
+
+
+class IntakeConstants:
+    MOTOR_PORT = 1
+
+    PISTON_FWD_CHANNEL = 0
+    PISTON_REV_CHANNEL = 1
+    INTAKE_VELOCITY = 0.5
+
+
+JOYSTICK_INDEX = 0

robotpyExamples/examples/UnitTest/robot.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+#
+# 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.
+#
+
+import wpilib
+
+import constants
+from subsystems.intake import Intake
+
+
+class MyRobot(wpilib.TimedRobot):
+    """The methods in this class are called automatically corresponding to each mode, as
+    described in the TimedRobot documentation. If you change the name of this class or the
+    package after creating this project, you must also update the Main.java file in the
+    project.
+    """
+
+    def __init__(self) -> None:
+        super().__init__()
+        self.intake = Intake()
+        self.joystick = wpilib.Joystick(constants.JOYSTICK_INDEX)
+
+    def teleopPeriodic(self) -> None:
+        """This function is called periodically during operator control."""
+        # Activate the intake while the trigger is held
+        if self.joystick.getTrigger():
+            self.intake.activate(constants.IntakeConstants.INTAKE_VELOCITY)
+        else:
+            self.intake.activate(0)
+
+        # Toggle deploying the intake when the top button is pressed
+        if self.joystick.getTop():
+            if self.intake.isDeployed():
+                self.intake.retract()
+            else:
+                self.intake.deploy()

robotpyExamples/examples/UnitTest/subsystems/intake.py

@@ -0,0 +1,36 @@
+#
+# 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.
+#
+
+import wpilib
+
+from constants import IntakeConstants
+
+
+class Intake:
+    def __init__(self) -> None:
+        self.motor = wpilib.PWMSparkMax(IntakeConstants.MOTOR_PORT)
+        self.piston = wpilib.DoubleSolenoid(
+            0,
+            wpilib.PneumaticsModuleType.CTRE_PCM,
+            IntakeConstants.PISTON_FWD_CHANNEL,
+            IntakeConstants.PISTON_REV_CHANNEL,
+        )
+
+    def deploy(self) -> None:
+        self.piston.setThrottle(wpilib.DoubleSolenoid.Value.FORWARD)
+
+    def retract(self) -> None:
+        self.piston.setThrottle(wpilib.DoubleSolenoid.Value.REVERSE)
+        self.motor.setThrottle(0)  # turn off the motor
+
+    def activate(self, velocity: float) -> None:
+        if self.isDeployed():
+            self.motor.setThrottle(velocity)
+        else:  # if piston isn't open, do nothing
+            self.motor.setThrottle(0)
+
+    def isDeployed(self) -> bool:
+        return self.piston.get() == wpilib.DoubleSolenoid.Value.FORWARD