Fix globalSummon with monitor:any moving to wrong monitor when desktop:toCurrent

[Criseda]

Summary of the Pull Request

When globalSummon is invoked with monitor:any and desktop:toCurrent, MoveWindowToDesktop may reposition the window to the monitor of the current foreground window instead of keeping it on its original monitor. This fix saves the window position before summoning and restores it after the desktop move completes.

References and Relevant Issues

Closes #20305

Detailed Description of the Pull Request / Additional comments

In AppHost::HandleSummon, when the combination of MonitorBehavior::InPlace (mapped from monitor:any) and MoveToCurrentDesktop=true is detected:

1. Save the window rect before calling SummonWindow
2. After MoveWindowToDesktop runs on the background thread, dispatch back to the UI thread and compare the current window origin to the saved origin
3. If the origin changed (indicating MoveWindowToDesktop moved the window to a different monitor), restore the saved position via SetWindowPos

The HWND handle is also extracted once at the top and reused throughout as a minor cleanup.

This approach was previously suggested by contributor @Weichenleeeee123 in the issue comments.

Validation Steps Performed

• Build passes with 0 errors (only pre-existing PRI263 warnings)
• Code formatting verified via Invoke-CodeFormat

PR Checklist

• Closes globalSummon with "monitor": "any" behaves as "monitor": "toCurrent" #20305
• Tests added/passed (no existing summon-specific tests)
• Documentation updated
• Schema updated (if necessary)

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[Criseda]

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