Add "Read more" link for Trusted Signing documentation

Introduced a new "Read more" link in the UI to provide users
with quick access to Microsoft Learn documentation on Trusted
Signing. Added a static string for the documentation URL in
`Globals.cs`. Updated `MainForm.Designer.cs` to include the
`linkLabelReadMoreTrustedSigning` control and its properties.

Implemented the `linkLabelReadMoreTrustedSigning_LinkClicked`
event handler in `MainForm.cs` to open the URL, log user
interaction, and handle potential errors with appropriate
messages and logging. These changes enhance user experience
and improve accessibility to relevant resources.

Author: michaelmsonne

src/SignToolGUI/Class/Globals.cs

@@ -35,6 +35,7 @@ internal class ToolStates
         internal class ToolStings
         {
             internal static string URLAzurePortalTrustedSigning = @"https://portal.azure.com/#browse/Microsoft.CodeSigning%2Fcodesigningaccounts";
+            internal static string URLMicrosoftLearnTrustedSigning = @"https://learn.microsoft.com/en-us/azure/trusted-signing/overview";
         }
 
 

src/SignToolGUI/Forms/MainForm.Designer.cs

@@ -3240,5 +3240,24 @@ private void ExportCommandScript()
                 Message("Failed to export command script: " + ex.Message, EventType.Error, 20101);
             }
         }
+
+        private void linkLabelReadMoreTrustedSigning_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
+        {
+            try
+            {
+                Process.Start(Globals.ToolStings.URLAzurePortalTrustedSigning);
+
+                // Log the opening of the URL message
+                Message("User clicked the 'Read more' link for Trusted Signing to open the URL: '" + Globals.ToolStings.URLMicrosoftLearnTrustedSigning + "'", EventType.Information, 1052);
+            }
+            catch (Exception ex)
+            {
+                // Show an error message if the URL could not be opened
+                MessageBox.Show(@"Failed to open the URL '" + Globals.ToolStings.URLAzurePortalTrustedSigning + "'. Error: " + ex.Message, @"Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+
+                // Log the error message
+                Message("Failed to open the URL: " + ex.Message, EventType.Error, 1041);
+            }
+        }
     }
 }