[DO NOT MERGE] - Mina Signer Experimental Release

[MartinMinkov]

This should not be merged.

This is a branch that is used to deploy the mina-signer-experimental package on NPM. Originally was branched off https://github.com/MinaProtocol/mina/pull/10726

Has all the crypto changes to make mina-signer work in a browser environment from the linked PR. In addition, we deploy this version of mina-signer to npm under the name mina-signer-unmaintained as an experimental package for developers to use mina-signer in the browser.

Currently compatible with SnarkyJS 0.5.1