fix: dialog.showMessageBox defaultid on Windows

[codebytere]

Description of Change

Closes #22600.

Fixes Windows message box default button handling.

On Windows, dialog.showMessageBox / showMessageBoxSync ignored defaultId when it was 0 (first button) and failed whenever the target button text matched a common button (OK/Yes/No/Cancel/etc.), because we always offset with kIDStart instead of using the native common button ID. This meant the default focus could be wrong. The fix accepts defaultId >= 0`, bounds‑checks it, and maps to the proper ID (common button ID or custom offset) before calling TaskDialogIndirect.

Using the following code:

dialog.showMessageBoxSync(null, {
    type:'warning',
    buttons: ['Yes', 'No'],
    defaultId: 1,
    cancelId: 1,
    title: 'Power Control',
    message: "Warning!"
});

Before

After

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Fixes Windows dialog.showMessageBox default button handling.