feat: Separate encoding swaps from encoding txs

This way the user is responsible for encoding the Tycho Router method inputs that are used as guardrails in execution.

Interface changes:
- Create EncodedSolution
- StrategyEncoder
  - don't need to know have permit2 or token_in_already_in_router as attributes anymore
  - encode_strategy returns EncodedSolution now (no method encoding done here now)
- TychoEncoder
  - add encode_solution() method. This is the recommended method for users
  - needs to have permit2, token_in_already_in_router and router_address as attributes
  - permit creation is made in the router now

Also:
- create encoding_utils.rs
- update all tests

Took 2 hours 42 minutes


Took 3 minutes

Took 13 minutes

src/encoding/errors.rs

@@ -20,6 +20,8 @@ pub enum EncodingError {
     FatalError(String),
     #[error("Recoverable error: {0}")]
     RecoverableError(String),
+    #[error("Not implemented: {0}")]
+    NotImplementedError(String),
 }
 
 impl From<io::Error> for EncodingError {