Refactor message entity and add validation

- Refactored the Message class in RazorPagesTestSample.Data to RazorPagesTestSample.
- Added validation for the text content of the message, ensuring it is required and has a maximum length of 250 characters.
Resolves #6

Author: fatihdurgut

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "sarif-viewer.connectToGithubCodeScanning": "off"
+}

src/Application/src/RazorPagesTestSample/Data/Message.cs

@@ -1,16 +1,27 @@
 using System.ComponentModel.DataAnnotations;
 
-namespace RazorPagesTestSample.Data
+/// <summary>
+/// Represents a message entity with an ID and text content.
+/// </summary>
+namespace RazorPagesTestSample
 {
-    #region snippet1
     public class Message
     {
+        /// <summary>
+        /// Gets or sets the unique identifier for the message.
+        /// </summary>
         public int Id { get; set; }
 
+        /// <summary>
+        /// Gets or sets the text content of the message.
+        /// </summary>
+        /// <remarks>
+        /// The text content is required and must be a string with a maximum length of 250 characters.
+        /// </remarks>
         [Required]
         [DataType(DataType.Text)]
-        [StringLength(200, ErrorMessage = "There's a 200 character limit on messages. Please shorten your message.")]
+        [StringLength(250, ErrorMessage = "There's a 250 character limit on messages. Please shorten your message.")]
         public string Text { get; set; }
     }
-    #endregion
-}
+
+}