changed capitalization in WinformsControlsTest namespace name

[Tanya-Solyanik]

• changed capitalization in WinformsControlsTest->WinFormsControlsTest namespace name

• added DesignerCategory("default") attribute to the test forms

  Microsoft Reviewers: Open in CodeFlow

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 74.40418%. Comparing base (ee5e3eb) to head (4ffd249).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #11505 +/- ## =================================================== + Coverage 74.40259% 74.40418% +0.00158% =================================================== Files 3030 3030 Lines 628044 628044 Branches 46808 46808 =================================================== + Hits 467281 467291 +10 + Misses 157407 157401 -6 + Partials 3356 3352 -4 ``` | [Flag](https://app.codecov.io/gh/dotnet/winforms/pull/11505/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/11505/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `74.40418% <0.00000%> (+0.00158%)` | :arrow_up: | | [integration](https://app.codecov.io/gh/dotnet/winforms/pull/11505/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `17.99121% <ø> (+0.00034%)` | :arrow_up: | | [production](https://app.codecov.io/gh/dotnet/winforms/pull/11505/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `47.23202% <ø> (+0.00350%)` | :arrow_up: | | [test](https://app.codecov.io/gh/dotnet/winforms/pull/11505/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `96.98788% <0.00000%> (ø)` | | | [unit](https://app.codecov.io/gh/dotnet/winforms/pull/11505/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `44.19339% <ø> (-0.01965%)` | :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.

[Olina-Zhang]

We can see this change in main branch of the cloned winforms repo: