[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/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