feat: Add loadAllocs cheatcode

[clabby]

Overview

Introduces a new cheatcode, loadAllocs, which allows for directly inserting accounts into the in-memory revm state from an allocs section of a standard genesis.json file.

Motivation

Several Layer 2s, including Optimism, allocate many proxies etc. in the genesis file. For example, take Base Mainnet's 8.76MB genesis file.

While it is possible to deploy all of these contracts manually in a test file's setUp function, it is slow, cumbersome, and rather easy to accidentally break parity.

Solution

To allow for quicker and more ergonomic test setups in situations like the above, I've added a new loadAllocs cheatcode. This takes a path to a JSON file containing only the allocs object within a standard genesis.json, and directly inserts these accounts into revm's journal.

Alloc File Schema

The alloc file is simply the allocs section of a standard Genesis JSON file - that is, HashMap<Address, GenesisAccount>, where GenesisAccount is defined in ethers-rs as:

/// An account in the state of the genesis block.
#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
pub struct GenesisAccount {
    #[serde(
        skip_serializing_if = "Option::is_none",
        deserialize_with = "deserialize_stringified_u64_opt",
        default
    )]
    pub nonce: Option<u64>,
    #[serde(deserialize_with = "deserialize_stringified_numeric")]
    pub balance: U256,
    #[serde(skip_serializing_if = "Option::is_none", default)]
    pub code: Option<Bytes>,
    #[serde(
        skip_serializing_if = "Option::is_none",
        deserialize_with = "from_unformatted_hex_map",
        default
    )]
    pub storage: Option<HashMap<H256, H256>>,
}

Testing

Accompanying tests for the new cheatcode have been added in testdata.

Metadata
closes #6126

[DaniPopes]

can you please keep style consistent with the rest of the cheatcodes here? Self destructure at the top and lowercase error message.

[DaniPopes]

This folder does not exist anymore

[Evalir]

Closing in favor of #6207