Updates tailscale/corp#25278
Adds definitions for new CLI commands getting added in v1.80. Refactors some pre-existing CLI commands within the `configure` tree to clean up code.
Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
Also capitalises the start of all ShortHelp, allows subcommands to be hidden
with a "HIDDEN: " prefix in their ShortHelp, and adds a TS_DUMP_HELP envknob
to look at all --help messages together.
Fixes#11664
Signed-off-by: Paul Scott <paul@tailscale.com>