[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/ElevatorExponentialProfile/robot.py

@@ -0,0 +1,54 @@
+#!/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 wpimath
+
+from examplesmartmotorcontroller import ExampleSmartMotorController
+
+
+class MyRobot(wpilib.TimedRobot):
+    kDt = 0.02
+
+    def __init__(self) -> None:
+        super().__init__()
+        self.joystick = wpilib.Joystick(1)
+        self.motor = ExampleSmartMotorController(1)
+        # Note: These gains are fake, and will have to be tuned for your robot.
+        self.feedforward = wpimath.SimpleMotorFeedforwardMeters(1, 1, 1)
+
+        # Create a motion profile with the given maximum voltage and characteristics kV, kA
+        # These gains should match your feedforward kV, kA for best results.
+        self.profile = wpimath.ExponentialProfileMeterVolts(
+            wpimath.ExponentialProfileMeterVolts.Constraints.fromCharacteristics(
+                10, 1, 1
+            )
+        )
+        self.goal = wpimath.ExponentialProfileMeterVolts.State(0, 0)
+        self.setpoint = wpimath.ExponentialProfileMeterVolts.State(0, 0)
+
+        # Note: These gains are fake, and will have to be tuned for your robot.
+        self.motor.setPID(1.3, 0.0, 0.7)
+
+    def teleopPeriodic(self) -> None:
+        if self.joystick.getRawButtonPressed(2):
+            self.goal = wpimath.ExponentialProfileMeterVolts.State(5, 0)
+        elif self.joystick.getRawButtonPressed(3):
+            self.goal = wpimath.ExponentialProfileMeterVolts.State(0, 0)
+
+        # Retrieve the profiled setpoint for the next timestep. This setpoint moves
+        # toward the goal while obeying the constraints.
+        next_state = self.profile.calculate(self.kDt, self.setpoint, self.goal)
+
+        # Send setpoint to offboard controller PID
+        self.motor.setSetpoint(
+            ExampleSmartMotorController.PIDMode.kPosition,
+            self.setpoint.position,
+            self.feedforward.calculate(next_state.velocity) / 12.0,
+        )
+
+        self.setpoint = next_state