Use of client module via MetaMask Snap for a dapp on Arbitrum testnet

[jzaki]

Implement bls-client functionality in a metamask snap (NB: "only available in MetaMask Flask", ie Chrome desktop only)

• receive regular transactions from an Arbitrum dapp (testnet first)
• show the tx details to the user
• with user confirmation, sign an operation containing the transaction (action)
• submit signed operation to aggregation server
• communicate completion to user and/or dapp

[kautukkundan]

Keeping it on hold as suggested by @jzaki. Will revisit later.