feat: Add EncodingError

Change method signatures to expect it and raise it where it makes sense

--- don't change below this line ---
ENG-4076 <#DTT#>

src/encoding/router_encoder.rs

@@ -1,6 +1,5 @@
-use anyhow::Error;
-
 use crate::encoding::{
+    errors::EncodingError,
     models::{Solution, Transaction},
     strategy_encoder::StrategySelector,
     user_approvals_manager::UserApprovalsManager,
@@ -8,6 +7,9 @@ use crate::encoding::{
 
 #[allow(dead_code)]
 pub trait RouterEncoder<S: StrategySelector, A: UserApprovalsManager> {
-    fn encode_router_calldata(&self, solutions: Vec<Solution>) -> Result<Vec<Transaction>, Error>;
-    fn handle_approvals(&self, solutions: &[Solution]) -> Result<Vec<Vec<u8>>, Error>;
+    fn encode_router_calldata(
+        &self,
+        solutions: Vec<Solution>,
+    ) -> Result<Vec<Transaction>, EncodingError>;
+    fn handle_approvals(&self, solutions: &[Solution]) -> Result<Vec<Vec<u8>>, EncodingError>;
 }