Create general functions for the wallets

• Create a normal wallet, parameters: userId (for generating the name of the wallet), and for saving in the db
• Create a multisig_wallet, parametes: userId's (same reason as above)
• Create HDKeys, when a normal/multisig wallet has to be create a HDKey has to be generated. When creating a multisigwallet only one of the keys has to be private: https://github.com/1200wd/bitcoinlib/blob/7f975a80aabd2d6e8b73c013d4ca6d0724fda54d/examples/wallets_multisig.py#L28 . Find a good way to generate this easily

---

• Create a multisig transaction
• When the others are signing retrieve the transaction from the database
• Check if the user already signed the transaction