🧪 Add unit tests for Grid TryGet and TrySet methods

[johnstrand]

🎯 What:
Added unit tests for Grid<T> in tests/GameUtils.Tests/Types/Collections/GridTests.cs, covering previously untested TryGet and TrySet methods.

📊 Coverage:

• TryGet with valid and out-of-bounds (int x, int y) and Vector2 parameters.
• TrySet with valid and out-of-bounds (int x, int y) and Vector2 parameters.
• Constructors (valid dimensions, invalid dimensions, custom data array initialization).
• Indexers (int coordinates and Vector2).
• Bounds checking (IsInBounds).
• Grid state modifications (Clear and Fill variants).
• GetEnumerator enumeration.

✨ Result:
Improves test coverage for Grid<T> collections and guarantees reliability for TryGet and TrySet paths.

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PR created automatically by Jules for task 11031793889680203678 started by @johnstrand

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