feat: Adapt SplitSwapStrategyEncoder to have optional permit2 logic

- If the signer_pk is not passed -> use the swap method that expects the tokens to be already in the Router
- If it is passed -> compute permit2 and use swap method that does the token in transfer
- Extend builder to have another shortcut
- Add integration test with contract
- Update bin (and simplified it) and quickstart

--- don't change below this line ---
ENG-4255 Took 1 hour 51 minutes

Took 2 minutes

Took 7 seconds

examples/quickstart/main.rs

@@ -23,7 +23,7 @@ fn main() {
     // Initialize the encoder
     let encoder = EVMEncoderBuilder::new()
         .chain(TychoCoreChain::Ethereum)
-        .tycho_router(swapper_pk, None)
+        .tycho_router_with_permit2(None, swapper_pk)
         .expect("Failed to create encoder builder")
         .build()
         .expect("Failed to build encoder");