Feature: Add Editor Screenshot Tool

[PatrickJnr]

Screenshot Tool & ScreenshotService Refactor

Adds a Screenshot Tool to the Editor and updates ScreenshotService so it can be used outside the Engine assembly.

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What changed

Editor Screenshot Tool

New dock: View → Docks → Screenshot

• One-click screenshots (save to disk, optional Steam upload)
• High-resolution presets: 4K, 8K, Square, plus custom sizes
• Toggle for adding screenshots to the Steam library

ScreenshotService

• RequestCapture() and TakeHighResScreenshot() are now public
  • Previously internal, which blocked access from Sandbox.Tools
• Added OnScreenshotCaptured event with file metadata
• Output cleanup:
  • PNG only (lossless)
  • Safe high-res defaults (16× MSAA)

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Screenshots

In Editor

Screenshot Tool Dock

[PatrickJnr]

@handsomematt / @lolleko

[antopilo]

I don't think screenshot should be it's own tool.

[DevulTj]

Would make for a suitable library for people who would want it, but I don't see us putting this in the engine.