Move various "examples" into snippets. Several examples that were less
than a full mechanism or robot were moved to snippets. `arcadedrive` and
`tankdrive` were removed in favor of their Gamepad variants. `hidrumble`
was removed due to being too simple. `potentiometerpid` was removed
because of low utility. `gyromecanum` replaced `mecanumdrive` for
deduplication and because very few teams run holonomic drivetrains
without gyros.
#8626 needs to switch to using reflection to load the robot class. Do
that with this PR so it's separate.
Also, remove the duplicated main files from the template, and instead
fixup vscode to handle this properly.
Easier then the last one that put everything in a sub namespace. By
prefixing the name less things break, and intellisense will be less
confusing to new users during the transition.