Extract hexDump function

src/util.h

@@ -246,6 +246,19 @@ enum class ExtendedChar {
     GreekSmallLetterPhi = 0xed,
 };
 
+String hexDump(String in) {
+    String out;
+    for (size_t i = 0; i < in.length(); ++i) {
+        auto hexChar = String(in[i], HEX);
+        if (hexChar.length() == 1) {
+            out.concat('0');
+        }
+        out.concat(hexChar);
+        out.concat(' ');
+    }
+    return out;
+}
+
 /*
  * Message syntax:
  * separator: ~