feat: Implement SplitSwapStrategyEncoder

The strategy works as follows:
- Manage approvals needed
- Compute min amount (if check amount is any):
  - if slippage is defined, apply slippage on the expected amount and take the min value between that and the check amount
  - if not, it's just the check amount
- Iterate through the swaps
  - call the corresponding swap encoder to encode the swap
  - add swap header (tokens indexes and split)
  - ple encode the swaps
- Add extra inputs (amounts, token addresses, min amount, (un)wrap, number of tokens and receiver)

Misc:
- Move executor address and selector encoding inside the SwapEncoder
- Add default executor_selector to SwapEncoder
- Pass router address inside the SplitSwapStrategyEncoder
- Move Permit2 inside the SplitSwapStrategyEncoder. It is a responsibility and a specificity of the strategy to need permit2 approvals

--- don't change below this line ---
ENG-4081 Took 1 hour 21 minutes

src/encoding/evm/utils.rs

@@ -1,4 +1,4 @@
-use alloy_primitives::{Address, Keccak256, U256};
+use alloy_primitives::{aliases::U24, Address, Keccak256, U256};
 use alloy_sol_types::SolValue;
 use num_bigint::BigUint;
 use tycho_core::Bytes;
@@ -13,7 +13,7 @@ pub fn bytes_to_address(address: &Bytes) -> Result<Address, EncodingError> {
     if address.len() == 20 {
         Ok(Address::from_slice(address))
     } else {
-        Err(EncodingError::InvalidInput(format!("Invalid ERC20 token address: {:?}", address)))
+        Err(EncodingError::InvalidInput(format!("Invalid address: {:?}", address)))
     }
 }
 
@@ -56,3 +56,12 @@ pub fn encode_input(selector: &str, mut encoded_args: Vec<u8>) -> Vec<u8> {
     call_data.extend(encoded_args);
     call_data
 }
+
+/// Converts a percentage to a `U24` value. The percentage is a `f64` value between 0 and 100.
+/// MAX_UINT24 corresponds to 100%.
+pub fn percentage_to_uint24(percentage: f64) -> U24 {
+    const MAX_UINT24: u32 = 16_777_215; // 2^24 - 1
+
+    let scaled = (percentage / 100.0) * (MAX_UINT24 as f64);
+    U24::from(scaled.round())
+}