feat: Add executor and selector to Swap

Add tests to Swap
Modify ExecutionDispatcher and TychoRouter to account for these changes

--- don't change below this line ---
ENG-4041 Took 57 minutes


Took 10 seconds

foundry/lib/LibSwap.sol

@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.28;
+
+library LibSwap {
+    /// Returns the InToken index into an array of tokens
+    function tokenInIndex(bytes calldata swap)
+        internal
+        pure
+        returns (uint8 res)
+    {
+        res = uint8(swap[0]);
+    }
+
+    /// The OutToken index into an array of tokens
+    function tokenOutIndex(bytes calldata swap)
+        internal
+        pure
+        returns (uint8 res)
+    {
+        res = uint8(swap[1]);
+    }
+
+    /// The relative amount of token quantity routed into this swap
+    function splitPercentage(bytes calldata swap)
+        internal
+        pure
+        returns (uint24 res)
+    {
+        res = uint24(bytes3(swap[2:5]));
+    }
+
+    /// The address of the executor contract
+    function executor(bytes calldata swap)
+        internal
+        pure
+        returns (address res)
+    {
+        res = address(uint160(bytes20(swap[5:25])));
+    }
+
+    /// The selector to be used of the executor contract
+    function executorSelector(bytes calldata swap)
+        internal
+        pure
+        returns (bytes4 res)
+    {
+        res = bytes4(swap[25:29]);
+    }
+
+    /// Remaining bytes are interpreted as protocol data
+    function protocolData(bytes calldata swap)
+        internal
+        pure
+        returns (bytes calldata res)
+    {
+        res = swap[29:];
+    }
+}