[CHANGE] Added old cipher implementation

Manager.YouTube/Util/Cipher/Operations/CipherReverse.cs

@@ -0,0 +1,18 @@
+using System.Text;
+
+namespace Manager.YouTube.Util.Cipher.Operations;
+
+public class CipherReverse : ICipherOperation
+{
+    public string Decipher(string cipherSignature)
+    {
+        var buffer = new StringBuilder(cipherSignature.Length);
+
+        for (var i = cipherSignature.Length - 1; i >= 0; i--)
+        {
+            buffer.Append(cipherSignature[i]);
+        }
+
+        return buffer.ToString();
+    }
+}

Manager.YouTube/Util/Cipher/Operations/CipherSlice.cs

@@ -0,0 +1,6 @@
+namespace Manager.YouTube.Util.Cipher.Operations;
+
+public class CipherSlice(int indexToSlice) : ICipherOperation
+{
+    public string Decipher(string cipherSignature) => cipherSignature[indexToSlice..];
+}

Manager.YouTube/Util/Cipher/Operations/CipherSwap.cs

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+using System.Text;
+
+namespace Manager.YouTube.Util.Cipher.Operations;
+
+public class CipherSwap(int indexToSwap) : ICipherOperation
+{
+    public string Decipher(string cipherSignature) => new StringBuilder(cipherSignature)
+    {
+        [0] = cipherSignature[indexToSwap],
+        [indexToSwap] = cipherSignature[0]
+    }.ToString();
+}

Manager.YouTube/Util/Cipher/Operations/ICipherOperation.cs

@@ -0,0 +1,6 @@
+namespace Manager.YouTube.Util.Cipher.Operations;
+
+public interface ICipherOperation
+{
+    string Decipher(string cipherSignature);
+}