[two_dimensional_scrollables] Add debug check for pinning out of bounds

[Piinks]

Fixes flutter/flutter#136833

This cleans up an old todo from when we added support for pinned rows and columns to TableView. It is possible for the pinned extents to exceed the viewport bounds, which would make scrolling impossible, and unpinned rows/columns inaccessible. This adds debug check during layout to catch this now.

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Code Review

This pull request updates the two_dimensional_scrollables package to version 0.4.1, introducing debug warnings for TableView when pinned rows or columns exceed or fully occupy the viewport dimensions. These warnings help identify configurations where unpinned content would be invisible. The changes include the implementation of _debugCheckPinnedExtent and a new suite of regression tests. Feedback suggests refactoring the tests to use setUp and tearDown for mocking debugPrint to reduce code duplication and improve maintainability.