chore(vc): Use a different signature library for managing attestations

[Maddiaa0]

Overview

For the current prototype, we are using viems wallet libraries as our signing library ( for ecdsa signatures over k1 ). Viem offers no raw signing abilities, and such all messages, even if 32 bytes are hashed again. And everything is dealt with in strings by default - generally not the vibe

[jxom]

Viem offers no raw signing abilities

This is not true. See raw here: https://viem.sh/docs/accounts/local/signMessage#message

[Maddiaa0]

Viem offers no raw signing abilities

This is not true. See raw here: https://viem.sh/docs/accounts/local/signMessage#message

We were using this. But this still uses EIP191 format, i meant having an option to not do that