improvement: self-trade check

[denverbaumgartner]

today: when placing match market-making trades there a self-trade check to make sure orders don't auto-match on the contract side but not on the client side. it would be really not nice 😞 if someone were to be in a situation where they accidentally submitted a lot of transactions that fail but still spend gas 🗼

soon: we should add checks client side to make sure that offers aren't submitted that can self match. for a lot of these additional safety checks I think we should give the user the option to opt-out if they want to (speed?). a lot of other paths to improve on the speed front before we get to that point IMO. additionally, i think we should have some way to monitor for bad fail-state scenarios and cut the cord if needed. some type of safety module? maybe this is baked into the nonce manager 🧙