JWS compact serialization

[tgross35]

RFC7515 section 7.1 specifies a compact (b64 encoded) serialization. I think this could probably be handled withJws::{from_compact, to_compact} functions

[tgross35]

On a related note, TryFrom<General> for Flattened could be useful

[sigmavirus24]

As far as I can tell, this is supported by Flattened::from_str.

I think what's missing is the to_compact support mentioned.

[sigmavirus24]

Although the Display trait does implement this:

JOSE/jose-jws/src/compact.rs

Lines 58 to 71 in 70423d5

	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
	let mut prot = alloc::string::String::new();
	if let Some(x) = self.signature.protected.as_ref() {
	prot = Base64UrlUnpadded::encode_string(x.as_ref());
	}
	let mut payl = alloc::string::String::new();
	if let Some(x) = self.payload.as_ref() {
	payl = Base64UrlUnpadded::encode_string(x);
	}
	let sign = Base64UrlUnpadded::encode_string(&self.signature.signature);
	write!(f, "{prot}.{payl}.{sign}")
	}