feat: Always classify settlements containing ERC1271 orders as unsafe

[harisang]

We noticed that settlements containing only user orders getting executed via CoWs/buffer trading can still revert with non-trivial probability when they contain ERC1271 orders, such as CoW AMM orders. Here are some recent reverts:

https://etherscan.io/tx/0x0d53fa8f3227abea94d61846a7ed63ef99bc760b6ebebed4685d2cf92f3eb59c

https://etherscan.io/tx/0x1884ea582d7831d74a95228ce998eff7335851a3eda2a5758586d8e6bba23bb0

https://etherscan.io/tx/0xd4bed4ec1bc40b837e176440de505a2a2f852d75b6ad1c94a3c8f810cff3c7fd

https://etherscan.io/tx/0x8a3be935806a02573b503901f1ffb062491e4fc25eccf06f0ccc311b3cf09cc2

https://etherscan.io/tx/0x327cf88e38797c2e5accc21de7dc5197bf45d6d94115d6550345a47ff2b97fca

https://etherscan.io/tx/0x5bb2fb0a2c30b3f024a3756b3fd7ae42eac3bc64fae82ad1d087bbc625f70899

https://etherscan.io/tx/0x75be368ca1ae5d898f51ad252cd1449433f24d5bccd739cd7495be6eefbbc6fc

https://etherscan.io/tx/0x750910d8adee1f8a93e9ffa13e3849b44b0ae880b0de28ed099e0202e0582fd7

Although not really a bug, we could improve our submission process by classifying such settlements as unsafe, and submitting them by default to MEV Blocker, instead of the public mempool.

[fleupold]

Not sure if we want to block this on #2215 but basically the settlement encoder currently classifies a settlement as revertable if it contains any interactions. This would need to be changed to also check for ERC1271 orders:

services/crates/solver/src/settlement.rs

Lines 174 to 181 in 6b32c72

	/// Calculates the risk level for settlement to be reverted
	pub fn revertable(&self) -> Revertable {
	if self.encoder.has_interactions() {
	Revertable::HighRisk
	} else {
	Revertable::NoRisk
	}
	}