Create a fund manager contract living on L2

[JamesANZ]

• Handle deposits and balances for users
• Move a certain percentage of the funds per cycle
• Move the funds on a specified interval e.g. weekly
• Handle withdrawals on a pro rata basis

[JamesANZ]

Update: for now we have decided on a simpler approach that is as follows:

1. User approves DCA manager contract to move their funds e.g. DAI
2. User signs multiple messages specifying how much of their position they wish to sell based on certain time lines e.g. 100 DAI per week for WETH
3. User gives signed messages to relayer
4. Relayer publishes them to the contract and the order gets swapped provided it meets the requirements