feat: support evm contract calls

[0xrusowsky]

adds support for EVM contract calls by enhancing the interface macro with 2 args (both optional from the user pov):

• compilation target: encodes the fn selector based on the rules of the compilation target. Available options are "r55" (default if uninformed) or "evm". For instance, fn set(&mut self, value: U256) would be hashed from:
  • set(uint256) on "evm"
  • set on "r55"
• rename: renames the fn name ("camelCase" is the only supported option)

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tested by manually loading the bytecode of a simple storage contract written in foundry to test x-contract calls in both directions:

• tx call to r55 contract > evm contract call
• tx call to evm contract > r55 contract call ( > evm contract call)

i believe that this proves that the execution changes made on:

• feat: impl contract calls #26

were enough to fully support cross contract calls, but happy to test more scenarios if needed (remember that @leonardoalt questioned whether the changes would be enough or not, so maybe worth increasing test coverage even more)

---

open questions:

• i'm manually mapping the rust (alloy primitives) types to solidity types, i couldn't find a better way to do it:

  // Helper function to convert rust types to their solidity equivalent
  // TODO: make sure that the impl is robust, so far only tested with "simple types"
  fn rust_type_to_sol_type(ty: &Type) -> Result<DynSolType, &'static str> {

• i'm manually creating a dummy value of the return type of the contract calls to determine an expected return size.
  • there must be better ways to do it
  • it won't work for dynamic types of unknown size
  • if i returned a size of 0 there was no memory allocation and txs were reverting as it trying to access slot 0 of the memory which is smaller than the BASE determined by the riscv emulator, so i forced a minimum size of 32bytes for the time being:

  // TODO: figure out a better way to get the return size
  // Create a dummy value to get its encoded size
  let dummy_value = <#return_ty>::default();
  let size = dummy_value.abi_encoded_size() as u64;
  let result = eth_riscv_runtime::call_contract(
     self.address,
     0_u64,
     &complete_calldata,
     if size == 0 { 32_u64 } else { size }
   )?;