Add SendKeys overload with delay; clean up using directives

A new overload of the SendKeys method has been added to the
G4.WebDriver.Remote.Uia namespace in the UiaDriver.cs file. This
method allows sending each character of the specified text as a key
input with a delay between each keystroke. The method takes two
parameters: text (the text to be sent as key inputs) and delay (the
delay to wait between sending each key).

In the UiaDriverTests.cs file, several using directives have been
removed: G4.WebDriver.Extensions, System, and System.Threading.

Author: gravity-api

src/G4.WebDriver.Remote.Uia/UiaDriver.cs

@@ -253,6 +253,25 @@ public void SendKeys(string text)
             SendKeys(repeat: 1, text);
         }
 
+        /// <summary>
+        /// Sends each character of the specified text as a key input with a delay between each keystroke.
+        /// </summary>
+        /// <param name="text">The text to be sent as key inputs.</param>
+        /// <param name="delay">The delay to wait between sending each key.</param>
+        public void SendKeys(string text, TimeSpan delay)
+        {
+            // Iterate through each character in the provided text.
+            foreach (var character in text)
+            {
+                // Send the current character as a key input.
+                // 'repeat: 1' indicates that the key is sent once.
+                SendKeys(repeat: 1, text: $"{character}");
+
+                // Wait for the specified delay before sending the next key.
+                Thread.Sleep(delay);
+            }
+        }
+
         /// <summary>
         /// Sends text input to the WebDriver server multiple times.
         /// </summary>

src/G4.WebDriver.Tests/UiaDriverTests.cs

@@ -1,12 +1,9 @@
 using G4.WebDriver.Models;
-using G4.WebDriver.Extensions;
 using G4.WebDriver.Remote.Uia;
 
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-using System;
 using System.IO;
-using System.Threading;
 
 namespace G4.WebDriver.Tests
 {