Integrate EIP-1271 to enable smart contract wallets to use Guild.xyz

[seichris]

Problem:
At the moment Guild.xyz can't be used by wallets such as Ambire Wallet, Argent and Gnosis Safe as guild.xyz doesn't allow smart contract wallets to sign messages.

Solution:
This can be easily resolved by integrating EIP-1271 (eips.ethereum.org/EIPS/eip-1271)).

Additionally, we at Ambire are soon releasing an npm library that handles signature validation for any signature type, including EIP 712 (typed data) support and EIP 1271 (smart contract signature) support - using it will automatically give you compatibility with Ambire, Gnosis Safe, Argent, Sequence and other SC wallets

Expected Result:
This will enable thousands of users to authenticate on guild.xyz' guilds using their existing wallets.