Fix TintColor FlipBook implementation and naming consistency

- Add missing _TINT_MAP_MODE_2D_ARRAY keyword to all shader files
- Rename TintColorMode.Texture2D to SingleTexture for consistency with BaseMapMode
- Fix tintColor variable initialization in ParticlesUber.hlsl
- Update all references to use SingleTexture instead of Texture2D
- Add documentation note about enum ordering differences due to backward compatibility

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Co-Authored-By: Claude <noreply@anthropic.com>

Author: Tatami