feat: Refactor TychoEncoder

We have a trait TychoEncoder and then two implementations: TychoRouterEncoder and TychoExecutorEncoder.
This way we go a level above with the decision if it is a direct execution or if it should use the tycho router.

- Created two builders: one for each tycho encoder
- Delete ExecutorStrategyEncoder and move code straight into the TychoExecutorEncoder
- Add validate_solution to trait TychoEncoder
- Move group_swaps.rs a level up
- Update tests and usage cases

Doing this we get rid of all that weird stuff we were doing before

--- don't change below this line ---
ENG-4306 Took 2 hours 6 minutes


Took 12 seconds

src/encoding/tycho_encoder.rs

@@ -14,8 +14,7 @@ pub trait TychoEncoder {
     ///
     /// # Returns
     /// * `Result<Vec<Transaction>, EncodingError>` - Vector of executable transactions
-    fn encode_router_calldata(
-        &self,
-        solutions: Vec<Solution>,
-    ) -> Result<Vec<Transaction>, EncodingError>;
+    fn encode_calldata(&self, solutions: Vec<Solution>) -> Result<Vec<Transaction>, EncodingError>;
+
+    fn validate_solution(&self, solution: &Solution) -> Result<(), EncodingError>;
 }