Update Accessibility test application

[Olina-Zhang]

Update Accessibility test app to fix these issues: https://github.com/dotnet/winforms/issues/11445, https://github.com/dotnet/winforms/issues/11436, https://github.com/dotnet/winforms/issues/11451, https://github.com/dotnet/winforms/issues/11448, https://github.com/dotnet/winforms/issues/11458 and https://github.com/dotnet/winforms/issues/11444

Proposed changes

https://github.com/dotnet/winforms/issues/11445: change groupBox ForeColor property https://github.com/dotnet/winforms/issues/11436: change tested Form's text property with adding "excluded this Form in Accessibility Test Pass" https://github.com/dotnet/winforms/issues/11451: enable toolStripContainer.TopToolStripPanel.TabStop and adjust tabIndex in order to can tab items and tab order correctly https://github.com/dotnet/winforms/issues/11448: adjust ToolStripButton's size to 24 24 if it is smaller than 24 24 https://github.com/dotnet/winforms/issues/11458 and https://github.com/dotnet/winforms/issues/11444: remove affected form to exclude in Accessibility test application

Microsoft Reviewers: Open in CodeFlow

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 74.40257%. Comparing base (5cefc3d) to head (65da424).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #11528 +/- ## =================================================== - Coverage 74.40876% 74.40257% -0.00620% =================================================== Files 3032 3032 Lines 628254 628196 -58 Branches 46832 46813 -19 =================================================== - Hits 467476 467394 -82 - Misses 157427 157447 +20 - Partials 3351 3355 +4 ``` | [Flag](https://app.codecov.io/gh/dotnet/winforms/pull/11528/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | Coverage Δ | | |---|---|---| | [Debug](https://app.codecov.io/gh/dotnet/winforms/pull/11528/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `74.40257% <ø> (-0.00620%)` | :arrow_down: | | [integration](https://app.codecov.io/gh/dotnet/winforms/pull/11528/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `17.98559% <ø> (-0.01673%)` | :arrow_down: | | [production](https://app.codecov.io/gh/dotnet/winforms/pull/11528/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `47.24387% <ø> (-0.01810%)` | :arrow_down: | | [test](https://app.codecov.io/gh/dotnet/winforms/pull/11528/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `96.96668% <ø> (-0.00088%)` | :arrow_down: | | [unit](https://app.codecov.io/gh/dotnet/winforms/pull/11528/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `44.20151% <ø> (-0.04222%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet#carryforward-flags-in-the-pull-request-comment) to find out more.

[Syareel-Sukeri]

The issues in the latest Accessibility test application in the winforms repository on the main branch have been verified and fixed. The test app now behaves as expected, consistent with the verification of the corresponding GitHub issues.