[cmd3] Add example and template projects for commands v3 and make hatchbot example idiomatic (#8887)

The `command3` example project contains a program that could plausibly
play in the 2026 rebuilt game. It includes nested mechanisms (`Intake`
has an inner `IntakeWrist` and `IntakeRoller` and is similar to the v2
superstructure concept), swerve drive with localization and path
following (albeit stubbed for sake of example), opmodes and
opmode-scoped commands, and command-scoped triggers.

The template projects are basic skeletons. The larger template includes
a basic command that just increments and prints a counter variable every
time it runs.

The hatchbot v3 example has been refactored to be more idiomatic:
- `RobotContainer` removed
- "Subsystem" names in packages, comments, and classes has been replaced
with "Mechanism"
- Some v2-specific comments and structures have been reworded or deleted
- The Drive mechanism now provides commands for arcade drive and driving
a distance, instead of exposing public methods that write directly to
hardware (which broke encapsulation and made it possible to issue
conflicting hardware requests)

wpilibjExamples/example_projects.bzl

@@ -24,6 +24,7 @@ EXAMPLE_FOLDERS = [
     "mecanumdriveposeestimator",
     "mechanism2d",
     "rapidreactcommandbot",
+    "rebuiltcmdv3",
     "romireference",
     "simpledifferentialdrivesimulation",
     "statespacearm",
@@ -87,6 +88,8 @@ SNIPPET_FOLDERS = [
 TEMPLATE_FOLDERS = [
     "commandv2",
     "commandv2skeleton",
+    "commandv3",
+    "commandv3skeleton",
     "educational",
     "opmode",
     "robotbaseskeleton",