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/strategy_encoder.rs

@@ -1,12 +1,25 @@
+use alloy::signers::local::PrivateKeySigner;
+use alloy_primitives::ChainId;
+use tycho_core::Bytes;
+
 use crate::encoding::{errors::EncodingError, models::Solution};
 
 #[allow(dead_code)]
 pub trait StrategyEncoder {
-    fn encode_strategy(&self, to_encode: Solution) -> Result<Vec<u8>, EncodingError>;
+    fn encode_strategy(
+        &self,
+        to_encode: Solution,
+        router_address: Bytes,
+    ) -> Result<Vec<u8>, EncodingError>;
     fn selector(&self, exact_out: bool) -> &str;
 }
 
 pub trait StrategySelector {
     #[allow(dead_code)]
-    fn select_strategy(&self, solution: &Solution) -> Box<dyn StrategyEncoder>;
+    fn select_strategy(
+        &self,
+        solution: &Solution,
+        signer: Option<PrivateKeySigner>,
+        chain_id: ChainId,
+    ) -> Result<Box<dyn StrategyEncoder>, EncodingError>;
 }