Report descriptions for .NET Framework WinForms ToolStrip menu items using UIA

[cary-rowen]

Link to issue number:

No issue. This was found while investigating #19335 and is separate from #20485.

Summary of the issue:

Classic .NET Framework Windows Forms ToolStrip menu items exposed through the native UIA provider can expose AccessibleDescription only through LegacyIAccessible. UIA FullDescription and HelpText are empty, so NVDA does not report the description.

Description of user facing changes:

NVDA now reports object descriptions for affected ToolStrip menu items.

Description of developer facing changes:

No public API changes.

Description of development approach:

Extend the existing UIA menu item description handling with a LegacyIAccessible description fallback. Standard UIA descriptions remain preferred. For affected .NET Framework WinForms ToolStripMenuItem providers, the fallback is used only when the standard description is missing or equals the object name. Descriptions equal to the name remain suppressed.

The fix is implemented directly in NVDAObjects.UIA.MenuItem. Cached UIA framework and provider metadata are used to limit the fallback to the affected .NET Framework WinForms ToolStripMenuItem providers, avoiding LegacyIAccessible queries for unrelated UIA menu items.

Testing strategy:

• Manual testing across the .NET Framework 4.5.2, 4.7.2, 4.8 and 4.8.1 samples, plus the .NET 8 sample.
• Unit tests cover standard UIA description precedence, LegacyIAccessible fallback, duplicate-name suppression, unsupported property values, and exclusion of WPF, modern .NET and non-ToolStrip providers.

Known issues with pull request:

None known.

Code Review Checklist:

• Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English
• API is compatible with existing add-ons.
• Security precautions taken.