Crypto providers

[grizzled lava]

So I was looking into removing the crypto provider logic from tokio-websockets (to also drop it in twilight later), turns out that isn't really possible atm because the crypto providers are used for SHA1 and I think that is fine. I will probably still continue to remove the crypto provider stuff, but... the feature flags will probably still stay around for choosing a SHA1 provider.

[jagged depot]

Yeah and it does not look like CryptoProviders have a generic way to check for and use sha1

[grizzled lava]

fun fact, graviola doesn't even implement SHA1

or at least not publicly exposed

anyways, I think we can entirely drop SHA1 if we get rid of the server and client code and instead point people at hyper