Draft: Implement Modal having a titlebar and moveable

[iamAbhi-916]

Description

Implement Modal having a titlebar and moveable

Type of Change

Erase all that don't apply.

• New feature (non-breaking change which adds functionality)

Why

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Resolves [Add Relevant Issue Here]
#14067

What

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Testing

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Changelog

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Microsoft Reviewers: Open in CodeFlow

[TatianaKapos]

Two things here

1. Make sure to test with USE_EXPERIMENTAL_WINUI3="true" aswell, in the future we will want to transition to the experimental_winui3 which uses different APIs
2. More work is needed to get Modal working with the titlebar's close button, try closing and reopening the modal to see