refactor(gui,api,logging): UI layout tweaks, cleanup, and improved diagnostics

- CbBxCamType now spans the full width of CbBxCameraModel
- BtnTest_Click moved to the bottom of AiQ_GUI.cs for easier testing/navigation
- Unused using directives removed across files
- Login credentials factored out and reused in MobileAPI.cs
- VLC.cs Capture function reviewed and superseded by TakeSnapshot
- InsertCamTab implementation updated to avoid use of `var`
- Misleading '// Non-ONVIF cameras' comment corrected
- Added Level.Debug logging, accessible only to developers, for detailed diagnostics

AiQ Tests/AiQTests.cs

@@ -8,7 +8,7 @@ public class AiQTests
             Helper.RestartApp();
 
         string LEDreply = await FlexiAPI.APIHTTPLED(MainForm.Instance.CamOnTest.IP, LEDPOWER.MID); // Set LED's to medium (0x30)
-
+        
         if (!LEDreply.Contains("Power levels set successfully"))
             MainForm.Instance.AddToActionsList($"LED level could not be set: {LEDreply}", Level.ERROR);
 

AiQ Tests/Diagnostics.cs

@@ -1,10 +1,4 @@
-using Renci.SshNet.Common;
-using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using System.Text;
-
-namespace AiQ_GUI.AiQ_Tests
+namespace AiQ_GUI.AiQ_Tests
 {
 
     public class TestingFunctions