Remove SHA1 implementation from @cosmjs/crypto

[webmaster128]

The SHA1 implementation in @cosmjs/crypto originates from IOV Core. I don't remember if it was ever used somewhere or if we just built it to show the nice generic HashFunction interface amd Hmac implementation.

I would like to switch to @noble/hashes because it would avoid pulling in all those dependencies written for node.js that make it very hard to work woth Webpack 5. And because it is well maintained and audited. This library does not have SHA1 as it is probably not needed.

As far as I can tell, SHA1 is not used in Cosmos.