[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/snippets/CANPDP/robot.py

@@ -0,0 +1,56 @@
+#!/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
+
+
+class MyRobot(wpilib.TimedRobot):
+    """
+    This is a sample program showing how to retrieve information from the Power
+    Distribution Panel via CAN. The information will be displayed under variables
+    through the SmartDashboard.
+    """
+
+    def __init__(self):
+        """Robot initialization function"""
+        super().__init__()
+
+        # Object for dealing with the Power Distribution Panel (PDP).
+        self.pdp = wpilib.PowerDistribution(0)
+
+        # Put the PDP itself to the dashboard
+        wpilib.SmartDashboard.putData("PDP", self.pdp)
+
+    def robotPeriodic(self):
+        # Get the current going through channel 7, in Amperes.
+        # The PDP returns the current in increments of 0.125A.
+        # At low currents the current readings tend to be less accurate.
+        current7 = self.pdp.getCurrent(7)
+        wpilib.SmartDashboard.putNumber("Current Channel 7", current7)
+
+        # Get the voltage going into the PDP, in Volts.
+        # The PDP returns the voltage in increments of 0.05 Volts.
+        voltage = self.pdp.getVoltage()
+        wpilib.SmartDashboard.putNumber("Voltage", voltage)
+
+        # Retrieves the temperature of the PDP, in degrees Celsius.
+        temperatureCelsius = self.pdp.getTemperature()
+        wpilib.SmartDashboard.putNumber("Temperature", temperatureCelsius)
+
+        # Get the total current of all channels.
+        totalCurrent = self.pdp.getTotalCurrent()
+        wpilib.SmartDashboard.putNumber("Total Current", totalCurrent)
+
+        # Get the total power of all channels.
+        # Power is the bus voltage multiplied by the current with the units Watts.
+        totalPower = self.pdp.getTotalPower()
+        wpilib.SmartDashboard.putNumber("Total Power", totalPower)
+
+        # Get the total energy of all channels.
+        # Energy is the power summed over time with units Joules.
+        totalEnergy = self.pdp.getTotalEnergy()
+        wpilib.SmartDashboard.putNumber("Total Energy", totalEnergy)