Remove Devolutions viewer dependencies

[mamoreau-devolutions]

Summary

• remove unused Devolutions controls and theme dependencies from ControlR.Viewer.Avalonia
• retain the DevExpress theme as an explicit dependency of the sample app that uses it
• add an explicit System.Reactive dependency required by the viewer implementation

Validation

• built ControlR.Viewer.Avalonia and ControlR.AvaloniaViewerExample
• inspected the generated ControlR.Viewer.Avalonia package metadata to confirm it contains neither Devolutions dependency

[github-actions]

Thank you so much for your interest in ControlR! I really appreciate you taking the time to contribute.

However, I am not accepting PRs at the moment for the following reasons:

Read-Only Mirror
For now, the public repository is a read-only mirror. This allows me to work on ideas and experiments in private and only reveal them when they're ready.

Legal and Financial Considerations
With Remotely, I found out that there are legal impliciations to accepting external contributions. Since I'm now depending on ControlR to be my primary source of income, it's less complicated and risky if I avoid external contributions for now.

Personal Working Style
During these early stages of the project, working solo will bring me the most amount of happiness and sense of accomplishment. It will allow me to move quickly and maintain a clear vision.

Reviewing AI Code
In my opinion, reviewing code consumes about 4 times as many "mental calories" compared to writing it. With the rise of AI, I'm worried that I'd spend the vast majority of my time reviewing AI-generated PRs, which would detract from my ability to keep the project moving forward.

I will begin accepting external contributions once ControlR reaches a more mature state and is financially self-sustaining. Thank you for understanding!

If you have ideas, suggestions, or found a bug, please feel free to open an issue instead. I'd love to hear your feedback!

Thank you again for your interest in the project! 🙏