Deterministic Safe and Deposit

[codynhat]

Make deposit into safe address before creation using CREATE2.

[codynhat]

Gnosis Safe supports other people creating a safe and sending transactions, kind of like meta transactions. This means the flow could actually be:

1. Calculate the deterministic address of the Safe before it is deployed. See https://github.com/safe-global/safe-core-sdk/blob/main/packages/safe-core-sdk/src/safeFactory/index.ts#L167
2. Renter makes a deposit of the trip payment token into this address
3. Relayer creates safe at the address and can receive a refund for gas from the funds in the safe. See the parameters here https://github.com/safe-global/safe-core-sdk/blob/main/packages/safe-core-sdk/src/safeFactory/index.ts#L26-L28
4. Future transactions made to the safe can be signed by owners and executed by relayer, who receives a refund for gas