Scenario cleanup

[tig]

Fixes

• Fixes #_____

Proposed Changes/Todos

• Todo 1

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• I've named my PR in the form of "Fixes #issue. Terse description."
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[Copilot]

Pull request overview

Removes two experimental UICatalog scenarios and tidies scenario categorization to better group Unicode-related demos within the Examples/UICatalog area.

Changes:

• Removed the ViewExperiments and LineCanvasExperiment scenarios.
• Re-categorized several scenarios under a new/consistent "Unicode" category.
• Added the "Runnable" category to the Dialogs scenario.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
Examples/UICatalog/Scenarios/ViewExperiments.cs	Deleted experimental scenario.
Examples/UICatalog/Scenarios/LineCanvasExperiment.cs	Deleted experimental LineCanvas scenario.
Examples/UICatalog/Scenarios/Unicode.cs	Switched category from "Controls" to "Unicode".
Examples/UICatalog/Scenarios/RuneWidthGreaterThanOne.cs	Removed "Controls" category; added "Unicode".
Examples/UICatalog/Scenarios/Dialogs.cs	Added "Runnable" category.
Examples/UICatalog/Scenarios/CombiningMarks.cs	Added "Unicode" category.
Examples/UICatalog/Scenarios/ChineseUI.cs	Added "Unicode" category.
Examples/UICatalog/Scenarios/CharacterMap/CharacterMap.cs	Added "Unicode" category.