add automation peer for UserControl

[baochenw]

This patch adds automation peer for UserControl.

What does the pull request do?

As #17423 described, Windows UI automation can not determine the correct control type of UserControl. The root cause is that no corresponding automation peer for it.

What is the current behavior?

LocalizedControlType is "none".

What is the updated/expected behavior with this PR?

LocalizedControlType is "custom".

Checklist

• Added unit tests (if possible)?
• Added XML documentation to any related classes?
• Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with user documentation

Breaking changes

None

Obsoletions / Deprecations

Fixed issues

Fixes #17423

[avaloniaui-bot]

You can test this PR using the following package version. 11.3.999-cibuild0053217-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[cla-avalonia]

• All contributors have signed the CLA.

[baochenw]

@cla-avalonia agree

[avaloniaui-bot]

You can test this PR using the following package version. 11.3.999-cibuild0053225-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[avaloniaui-bot]

You can test this PR using the following package version. 11.3.999-cibuild0053245-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[avaloniaui-bot]

You can test this PR using the following package version. 11.3.999-cibuild0053249-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[baochenw]

cibuild0053249

Verified with this build:

Name:	"TestName"
ControlType:	UIA_CustomControlTypeId (0xC369)
LocalizedControlType:	"custom"
BoundingRectangle:	{l:1234 t:866 r:1909 b:1316}
IsEnabled:	true
IsOffscreen:	false
IsKeyboardFocusable:	false
HasKeyboardFocus:	false
ProcessId:	24224
RuntimeId:	[2A.150A7E.4.2B86539]
AutomationId:	"TestCustomControl"
FrameworkId:	"Avalonia"
ClassName:	"MyControl"