Add GlobalUsings.cs with project-wide using directives for Algorithms folder (#522)

Author: KaranChadha10

Algorithms/Crypto/Digests/AsconDigest.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Runtime.CompilerServices;
 using Algorithms.Crypto.Utils;
 

Algorithms/Crypto/Digests/IDigest.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Algorithms.Crypto.Digests;
 
 /// <summary>

Algorithms/Crypto/Digests/Md2Digest.cs

@@ -1,6 +1,4 @@
-using System;
-
-namespace Algorithms.Crypto.Digests;
+namespace Algorithms.Crypto.Digests;
 
 /// <summary>
 /// MD2 is a cryptographic hash function that takes an input message and produces a 128-bit output, also called a message

Algorithms/Crypto/Exceptions/CryptoException.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Algorithms.Crypto.Exceptions;
 
 /// <summary>

Algorithms/Crypto/Exceptions/DataLengthException.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Algorithms.Crypto.Exceptions;
 
 /// <summary>

Algorithms/Crypto/Exceptions/OutputLengthException.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Algorithms.Crypto.Exceptions;
 
 /// <summary>

Algorithms/Crypto/Paddings/IBlockCipherPadding.cs

@@ -1,6 +1,4 @@
-using System;
-
-namespace Algorithms.Crypto.Paddings;
+namespace Algorithms.Crypto.Paddings;
 
 /// <summary>
 /// A common interface that all block cipher padding schemes should follow.

Algorithms/Crypto/Paddings/Iso10126D2Padding.cs

@@ -1,7 +1,4 @@
-using System;
-using System.Security.Cryptography;
-
-namespace Algorithms.Crypto.Paddings;
+namespace Algorithms.Crypto.Paddings;
 
 /// <summary>
 /// <para>

Algorithms/Crypto/Paddings/Iso7816D4Padding.cs

@@ -1,6 +1,4 @@
-using System;
-
-namespace Algorithms.Crypto.Paddings;
+namespace Algorithms.Crypto.Paddings;
 
 /// <summary>
 /// <para>

Algorithms/Crypto/Paddings/Pkcs7Padding.cs

@@ -1,6 +1,4 @@
-using System;
-
-namespace Algorithms.Crypto.Paddings;
+namespace Algorithms.Crypto.Paddings;
 
 /// <summary>
 /// <para>