Add HexEncode to C#

(cherry picked from commit 6b54d7dde1)

modules/mono/glue/GodotSharp/GodotSharp/Core/Color.cs

@@ -695,31 +695,10 @@ namespace Godot
             return ig;
         }
 
-        private String ToHex32(float val)
+        private string ToHex32(float val)
         {
-            int v = Mathf.RoundToInt(Mathf.Clamp(val * 255, 0, 255));
-
-            var ret = string.Empty;
-
-            for (int i = 0; i < 2; i++)
-            {
-                char c;
-                int lv = v & 0xF;
-
-                if (lv < 10)
-                {
-                    c = (char)('0' + lv);
-                }
-                else
-                {
-                    c = (char)('a' + lv - 10);
-                }
-
-                v >>= 4;
-                ret = c + ret;
-            }
-
-            return ret;
+            byte b = (byte)Mathf.RoundToInt(Mathf.Clamp(val * 255, 0, 255));
+            return b.HexEncode();
         }
 
         internal static bool HtmlIsValid(string color)

modules/mono/glue/GodotSharp/GodotSharp/Core/StringExtensions.cs

@@ -454,6 +454,53 @@ namespace Godot
             return hashv;
         }
 
+        /// <summary>
+        /// Returns a hexadecimal representation of this byte as a string.
+        /// </summary>
+        /// <param name="bytes">The byte to encode.</param>
+        /// <returns>The hexadecimal representation of this byte.</returns>
+        internal static string HexEncode(this byte b)
+        {
+            var ret = string.Empty;
+
+            for (int i = 0; i < 2; i++)
+            {
+                char c;
+                int lv = b & 0xF;
+
+                if (lv < 10)
+                {
+                    c = (char)('0' + lv);
+                }
+                else
+                {
+                    c = (char)('a' + lv - 10);
+                }
+
+                b >>= 4;
+                ret = c + ret;
+            }
+
+            return ret;
+        }
+
+        /// <summary>
+        /// Returns a hexadecimal representation of this byte array as a string.
+        /// </summary>
+        /// <param name="bytes">The byte array to encode.</param>
+        /// <returns>The hexadecimal representation of this byte array.</returns>
+        public static string HexEncode(this byte[] bytes)
+        {
+            var ret = string.Empty;
+
+            foreach (byte b in bytes)
+            {
+                ret += b.HexEncode();
+            }
+
+            return ret;
+        }
+
         // <summary>
         // Convert a string containing an hexadecimal number into an int.
         // </summary>