Updated outdated information in Blazor UG

[Backiaraj]

Updated outdated information in Blazor UG.

1. Appearance --> Themes
2. UI Kit --> Build your First Blazor app with blocks
3. Visual Studio Integration --> Overview, Template Studio

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: 985454-UG

[SyncfusionBuild]

CI Status: SUCCESS ✅
Source Compilation: SUCCESS ✅
Build Location: 985454-UG
Technical Error(s): 0
Spelling Error(s): 0
Image Alt Text Error(s): 0
Image Size Error(s): 0
Image Name Error(s): 0
Front matter Error(s): 0
File Path Error(s): 0
CodeSnippet File Path Missing Error(s): 0
Toc Anchor Tags Validation Error(s): 0
MD Tag Validation Error(s): 0