[epic] Gnosis Safe and CowSwap

[anxolin]

Overview

This epic contains some issues and suggestions to promote the use of CowSwap and offer Gnosis Safe a better trading experience.

Context

CowSwap is releasing Smart Contract support, and as part of this new release, it's adding Gnosis Safe tailored UX meaning you will be able to get a better context on the state of the Gnosis Safe transactions within CowSwap. 🎉 See the release notes for this new version in: https://github.com/gnosis/cowswap/releases

We believe CowSwap is the best way to trade for Gnosis Safe users, and this is why:

• Reverted Transactions: Users will never get reverted transactions. In others, will happen all the time! (it will happen as soon as the price moves beyond your slippage tolerance, which is common in a volatile environment)
• You can use tight slippage without fear: Users don’t need to set high slippage to avoid reverted transactions (☝️). Note that setting a high slippage tolerance in your trade for other exchanges will be fresh meat for the MEV extraction bots
• You can use high slippage without fear: User will want to set high slippage tolerances for their Gnosis Safe trades though, since it can take a bit of time for all the signers to approve the trade. If you do this in CowSwap you will be better protected for three reasons: (1) Coincidence of Wants already reduce the exploitable MEV (2) Solvers will send solutions with much tighter slippages, so they won't use all the slippage tolerance (3) MEV risk is at the expense of the solver, not the user, and they use FlashBots API to further protected themselves.
• Get the best price, at execution time: Users of other exchanges need to pre-commit to a execution paths when they create the safe transaction (creation time), however this "best trade at creation time" might not be the "best trade at execution time" specially in a multisig environment where there are some delays of minutes, or even hours. Liquidity moves in seconds, so the later you calculate the best path the better. In CowSwap your order is an intent to trade at a given price, but the final price will be always equal or better than that, and calculated at execution time
• Tailored UI: Tight integration with the UI, so you will get a nice context on what is the state of the Gnosis Safe transaction already in CowSwap. It works with IOS app, and the web.
• CoW - Peer to Peer trading: We do Coincidence of Wants, so u might even get a better price than AMM, just because users will trade directly without paying the liquidity pool fee.

See also:

• https://gnosisinc.slack.com/archives/C63LQTGNB/p1636721773081900

Issues

Blocker:

• [x] #2999

Good to have:

• [ ] https://github.com/gnosis/safe-landing-page/issues/3000
• [ ] https://github.com/gnosis/safe-landing-page/issues/3001
• [x] https://github.com/gnosis/safe-react/issues/970
• [ ] #3002
• [ ] #3003