Extract U256Ext implementations into the numbers crate (#4030)

# Description
As noted in #4010, several U256Ext utility implementations are scattered
across different crates in the codebase, some of which are duplicated.
This PR moves all of them into a single U256Ext trait under the
`numbers` crate. No logic changes. As a result, easier to keep
everything in one place, no duplicated logic.

Author: squadgazzz

crates/autopilot/src/domain/eth/mod.rs

@@ -1,7 +1,8 @@
 pub use alloy::primitives::{Address, B256, U256};
 use {
-    crate::{domain, util::conv::U256Ext},
+    crate::domain,
     derive_more::{Display, From, Into},
+    number::u256_ext::U256Ext,
 };
 
 /// ERC20 token address for ETH. In reality, ETH is not an ERC20 token because

crates/autopilot/src/domain/settlement/mod.rs

@@ -351,17 +351,15 @@ pub struct ExecutionEnded {
 #[cfg(test)]
 mod tests {
     use {
-        crate::{
-            domain::{
-                self,
-                auction,
-                eth,
-                settlement::{OrderMatchKey, trade_to_key},
-            },
-            util::conv::U256Ext,
+        crate::domain::{
+            self,
+            auction,
+            eth,
+            settlement::{OrderMatchKey, trade_to_key},
         },
         alloy::{eips::BlockId, primitives::address},
         hex_literal::hex,
+        number::u256_ext::U256Ext,
         std::collections::{HashMap, HashSet},
         winner_selection::{self as ws, state::RankedItem},
     };

crates/autopilot/src/domain/settlement/trade/math.rs

@@ -1,19 +1,17 @@
 pub use error::Error;
 use {
     super::ExecutedProtocolFee,
-    crate::{
-        domain::{
-            self,
-            OrderUid,
-            auction::{self, order},
-            eth,
-            fee,
-            settlement::transaction::{ClearingPrices, Prices},
-        },
-        util::conv::U256Ext,
+    crate::domain::{
+        self,
+        OrderUid,
+        auction::{self, order},
+        eth,
+        fee,
+        settlement::transaction::{ClearingPrices, Prices},
     },
     error::Math,
     num::{CheckedAdd, CheckedDiv, CheckedMul, CheckedSub},
+    number::u256_ext::U256Ext,
     std::collections::HashMap,
 };
 

crates/autopilot/src/util/conv.rs

@@ -1,7 +1,6 @@
 use url::Url;
 
 mod bytes;
-pub mod conv;
 
 pub use self::bytes::Bytes;
 

crates/autopilot/src/util/mod.rs

@@ -12,22 +12,20 @@ use {
         order::{self, Side},
         trade::CustomClearingPrices,
     },
-    crate::{
-        domain::{
-            competition::{
-                PriceLimits,
-                auction,
-                order::FeePolicy,
-                solution::{
-                    error,
-                    fee::{self, adjust_quote_to_order_limits},
-                },
+    crate::domain::{
+        competition::{
+            PriceLimits,
+            auction,
+            order::FeePolicy,
+            solution::{
+                error,
+                fee::{self, adjust_quote_to_order_limits},
             },
-            eth,
         },
-        util::conv::u256::U256Ext,
+        eth,
     },
     alloy::primitives::ruint::UintTryFrom,
+    number::u256_ext::U256Ext,
 };
 
 pub fn compute_score(

crates/driver/src/domain/competition/solution/scoring.rs

@@ -1,13 +1,13 @@
-use crate::{
-    domain::{
+use {
+    crate::domain::{
         competition::{
             self,
             order::{self, FeePolicy, SellAmount, Side, TargetAmount, Uid},
             solution::error::{self, Math},
         },
         eth::{self, Asset},
     },
-    util::conv::u256::U256Ext,
+    number::u256_ext::U256Ext,
 };
 
 /// A trade which executes an order as part of this solution.

crates/driver/src/domain/competition/solution/trade.rs

@@ -1,7 +1,8 @@
 use {
-    crate::util::{Bytes, conv::u256::U256Ext},
+    crate::util::Bytes,
     alloy::rpc::types::TransactionRequest,
     derive_more::{From, Into},
+    number::u256_ext::U256Ext,
     solvers_dto::auction::FlashloanHint,
     std::{
         collections::{HashMap, HashSet},

crates/driver/src/domain/eth/mod.rs

@@ -9,10 +9,10 @@ use {
             liquidity,
         },
         infra::{config::file::FeeHandler, solver::ManageNativeToken},
-        util::conv::{rational_to_big_decimal, u256::U256Ext},
     },
     app_data::AppDataHash,
     model::order::{BuyTokenDestination, SellTokenSource},
+    number::{conversions::rational_to_big_decimal, u256_ext::U256Ext},
     std::collections::HashMap,
 };
 

crates/driver/src/infra/solver/dto/auction.rs

@@ -1,10 +1,10 @@
 //! Test cases.
 
 use {
-    crate::{domain::eth, util::conv::u256::U256Ext},
+    crate::domain::eth,
     bigdecimal::{BigDecimal, FromPrimitive, Signed, num_traits::CheckedMul},
     num::BigRational,
-    number::conversions::big_decimal_to_big_rational,
+    number::{conversions::big_decimal_to_big_rational, u256_ext::U256Ext},
     std::str::FromStr,
 };