feat: Add evm feature gate

- Move all evm code inside evm directory
- StrategyEncoder:
  - Kept StrategyEncoder trait but created a new one: EVMStrategyEncoder to implement encode_protocol_header (that is evm specific).
  - All StrategyEncoders implement both traits now
  - Renamed DefaultStrategySelector -> EVMStrategySelector
- RouterEncoder:
  - Created a RouterEncoder trait and a EVMRouterEncoder that implements it
- Moved utils inside evm directory as well
- Renamed config.json -> executor_addresses.json and moved it to a higher config directory
- Make alloy optional and dependent on the evm feature gate

--- don't change below this line ---
ENG-4075 <#DTT#>

src/encoding/mod.rs

@@ -1,7 +1,7 @@
-mod approvals;
+#[cfg(feature = "evm")]
+mod evm;
 mod models;
 mod router_encoder;
 mod strategy_encoder;
-mod strategy_selector;
 mod swap_encoder;
-mod utils;
+mod user_approvals_manager;