[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/ElevatorProfiledPID/robot.py

@@ -0,0 +1,53 @@
+#!/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 math
+
+import wpilib
+import wpimath
+
+
+class MyRobot(wpilib.TimedRobot):
+    kDt = 0.02
+    kMaxVelocity = 1.75
+    kMaxAcceleration = 0.75
+    kP = 1.3
+    kI = 0.0
+    kD = 0.7
+    kS = 1.1
+    kG = 1.2
+    kV = 1.3
+
+    def __init__(self) -> None:
+        super().__init__()
+        self.joystick = wpilib.Joystick(1)
+        self.encoder = wpilib.Encoder(1, 2)
+        self.motor = wpilib.PWMSparkMax(1)
+
+        # Create a PID controller whose setpoint's change is subject to maximum
+        # velocity and acceleration constraints.
+        self.constraints = wpimath.TrapezoidProfile.Constraints(
+            self.kMaxVelocity, self.kMaxAcceleration
+        )
+        self.controller = wpimath.ProfiledPIDController(
+            self.kP, self.kI, self.kD, self.constraints, self.kDt
+        )
+        self.feedforward = wpimath.ElevatorFeedforward(self.kS, self.kG, self.kV)
+
+        self.encoder.setDistancePerPulse(1 / 360 * 2 * math.pi * 1.5)
+
+    def teleopPeriodic(self) -> None:
+        if self.joystick.getRawButtonPressed(2):
+            self.controller.setGoal(5)
+        elif self.joystick.getRawButtonPressed(3):
+            self.controller.setGoal(0)
+
+        # Run controller and update motor output
+        self.motor.setVoltage(
+            self.controller.calculate(self.encoder.getDistance())
+            + self.feedforward.calculate(self.controller.getSetpoint().velocity)
+        )