Add ehthumbs_vista.db as Windows thumbnail cache file

As Windows Vista Media Center thumbnails

References:

- https://nctritech.wordpress.com/tag/ehthumbs_vista-db/
- https://thumbsviewer.github.io/
- https://www.file-extensions.org/db-file-extension-windows-thumbnail-database

Global/Windows.gitignore

-# Windows image file caches
+# Windows thumbnail cache files
 Thumbs.db
 ehthumbs.db
+ehthumbs_vista.db
 
 # Folder config file
 Desktop.ini