Refactor to simplify OpenXR sample

[yl-msft]

Refactor the sample so it's easier to integrate OpenXR sample

Description

QRCode sample

Testing

Tested on HL2

Type of change

• [x] Improvement refactoring

Supported platforms

HL2

• [ ] All UWP platforms
• [ ] Desktop
• [x] Holographic
• [ ] IoT
• [ ] Xbox
• [ ] 10X

Supported languages

• [x] C#
• [ ] C++/WinRT

[Morgan-6Freedom]

I really loved to see that merged as soon as possible because I have a HL2 app with QRCode tracking that works with OpenXR and I need this version 🙏