date: Show timezone abbreviation

[howjmay]

Introduce a new package which meet the libc behavior. Close #3756

[tertsdiepraam]

There's some relevant discussion in: https://github.com/uutils/coreutils/pull/3762

It might be important to note that this crate doesn't just match the behaviour, it is glibc's strftime. That's not really a problem, but I'd prefer a pure Rust solution of course. I'm confused about the license of the crate though, because it's MIT, but glibc is LGPL, though I suppose those are compatible. For localized time and date, we could move to icu4x's datetime formatting at some point.

[sylvestre]

@howjmay any update on this ? thanks or should we just close the PR