[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/HatchbotTraditional/commands/halvedrivevelocity.py

@@ -0,0 +1,20 @@
+#
+# 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 commands2
+
+from subsystems.drivesubsystem import DriveSubsystem
+
+
+class HalveDriveVelocity(commands2.Command):
+    def __init__(self, drive: DriveSubsystem) -> None:
+        self.drive = drive
+
+    def initialize(self) -> None:
+        self.drive.setMaxOutput(0.5)
+
+    def end(self, interrupted: bool) -> None:
+        self.drive.setMaxOutput(1.0)