meta(anvil): `anvil-core` internal types removal

[Evalir]

The objective is to deduplicate the internal anvil types in anvil-core, used for storage and internal representation of state and phase out ethers. This involves:

• Removing the duplicated types in anvil-core which are now included in alloy-consensus crate alloy-rs/alloy#83
• Using the new alloy signers
• Migrating any custom needed anvil internal types (e.g ImpersonatedTransaction) to alloy.
• Migrating anvil's txpool/execution logic to use alloy.

Milestones on (anvil-core/anvil):

• ethers_compat.rs phased out
• block.rs phased out as duplicate
• pubsub.rs phased out as duplicate chore(anvil): remove ethers usage on subscription #6775
• state.rs phased out as duplicate chore(anvil): use alloy state override and remove ethers state override #6766
• cheats.rs cheats manager migrated chore(anvil): migrate cheatsmanager to alloy #6767
• receipt.rs phased out as duplicate by using the new receipt type in Alloy Consensus
• subscription.rs types migrated to use alloy-rpc types, consensus or core types wherever needed
• trie.rs migrated (migration needed for eth_getProof endpoint)
• utils.rs migrated to using alloy rlp encoding instead of parity rlp.
• anvil's executor.rs migrated to use alloy types.
• all ToAlloy/ToEthers conversions in anvil removed
• fastrlp dropped
• ethers removed from tests.

The result of this is that we will end up removing all the remaining ToAlloy/ToEthers conversions in anvil, as we won't longer have the separation between alloy-based rpc types and ethers-based internal types, but rather both will come from alloy-rs/alloy, and use the alloy primitive types. This allows us to drop ethers completely from anvil

[Evalir]

Closing as this is strictly related to anvil-core—the only work remaining is on the main anvil crate, for tests.