Unify mempool configs

[MartinquaXD]

Description

Especially on gnosis chain the reference driver struggled to bring solutions on chain. The issue seems to have been poor transaction gossiping of the 1 configured RPC. The fix was to configure multiple mempools at once. This ended up looking pretty weird with the current code because the only way how you can configure an RPC URL explicitly is by using the mevblocker variant of the mempool enum. This doesn't make sense since a) there is no mevblocker on gnosis chain and b) even on mainnet there is only 1 mevblocker.

Changes

This PR removes the mempool enum and replaces it with a struct that is flexible enough to configure an actual mevblocker endpoint but also multiple regular RPC nodes.

Since this is changing the driver config file in a backwards incompatible way this needs to be merged together with the corresponding infra PR updating the config format.

How to test

updated e2e and driver tests should still pass

[squadgazzz]

LGTM

[squadgazzz]

Does it make sense to add the mempool name into this config

services/crates/driver/src/infra/mempool/mod.rs

Lines 15 to 25 in 8440650

	#[derive(Debug, Clone)]
	pub struct Config {
	pub min_priority_fee: eth::U256,
	pub gas_price_cap: eth::U256,
	pub target_confirm_time: std::time::Duration,
	pub retry_interval: std::time::Duration,
	pub kind: Kind,
	/// Optional block number to use when fetching nonces. If None, uses the
	/// web3 lib's default behavior, which is `latest`.
	pub nonce_block_number: Option<web3::types::BlockNumber>,
	}

, so its name will be logged in this span?

services/crates/driver/src/domain/mempools.rs

Line 55 in a18d1d9

.instrument(tracing::info_span!("mempool", kind = mempool.to_string()))

UPD, it should probably be a part of the kind then:

services/crates/driver/src/infra/mempool/mod.rs

Line 73 in 8440650

write!(f, "Mempool({})", self.config.kind.format_variant())

[MartinquaXD]

Each mempool already has a name. Logging it happens via the Display impl here.

[squadgazzz]

I somehow missed that, thanks!

[jmg-duarte]

LGTM but I have a question