Display short help menu when `--help` is used (#4772)
I feel like I'm always drowning in the help output from `uv` because we
have so many options.
I basically agree with the commentary in
https://github.com/clap-rs/clap/issues/4687 that having different
behaviors for `-h` and `--help` is surprising. I think `--help` is more
obvious for users and I want to optimize for that experience.
This roughly matches the help menus in Cargo and pip.
The `uv help` command can be used for long help. In #4906 and #4909 we
improve that command.
Extends #4904 which adds test cases for the existing behavior.
