feat: Add ChainId model

Remove to_chain_id helper method

--- don't change below this line ---
ENG-4081 Took 28 minutes

src/encoding/evm/models.rs

@@ -0,0 +1,20 @@
+use tycho_core::models::Chain;
+
+pub struct ChainId(u64);
+
+impl ChainId {
+    pub fn id(&self) -> u64 {
+        self.0
+    }
+}
+
+impl From<Chain> for ChainId {
+    fn from(chain: Chain) -> Self {
+        match chain {
+            Chain::Ethereum => ChainId(1),
+            Chain::ZkSync => ChainId(324),
+            Chain::Arbitrum => ChainId(42161),
+            Chain::Starknet => ChainId(0),
+        }
+    }
+}