[OB2 Native] Icon & updater changes

Hey, Some minor improvements if possible

• Make a small change in Native’s Icon so we don’t mix it up with Web version
• Add a “Check for update” button in home page for quick access
• Button “Delete all proxies” is missing in Native version

With current configuration I currently have 4 OB2 icons on my taskbar with same appearance (It’s good for some mind practice though)

- OB2 Native
- OB2 Native Updater
- OB2 Web UI Console
- OB2 Web UI Updater

Added to github !