Fixed Percent delimiter for hex encoding (#2137)

Co-authored-by: GCHQ Developer 85297 <95289555+C85297@users.noreply.github.com>

src/core/lib/Hex.mjs

@@ -33,7 +33,7 @@ export function toHex(data, delim=" ", padding=2, extraDelim="", lineSize=0) {
     if (data instanceof ArrayBuffer) data = new Uint8Array(data);
 
     let output = "";
-    const prepend = (delim === "0x" || delim === "\\x");
+    const prepend = (delim === "0x" || delim === "\\x" || delim === "%");
 
     for (let i = 0; i < data.length; i++) {
         const hex = data[i].toString(16).padStart(padding, "0");

tests/operations/tests/Hex.mjs

@@ -43,6 +43,20 @@ TestRegister.addTests([
             }
         ]
     },
+    {
+        name: "ASCII to Hex with percent deliminator",
+        input: "aberystwyth",
+        expectedOutput: "%61%62%65%72%79%73%74%77%79%74%68",
+        recipeConfig: [
+            {
+                "op": "To Hex",
+                "args": [
+                    "Percent",
+                    0
+                ]
+            }
+        ]
+    },
     {
         name: "ASCII to 0x Hex with comma and line breaks",
         input: "aberystwyth",