[megathread] Chromium parity for tab drag/drop

_maintainer edit_

This is blocked on a TabView v3 from WinUI.

```[tasklist]
### Tasks
* [ ] Tabs should make a new window as soon as their torn out
* [ ] Torn-out tabs need to be able to snap to snap positions (maximized, snap layouts) without dropping first
* [ ] Multiple tabs can't be dragged/dropped all at once
* [ ] Dragging a tab in a window with a single tab should just drag the window
```

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Uploaded a video to show exactly what I'm talking about. In the video below I'm comparing tab tear out and joining with Microsoft Edge. Windows Terminal's tab experience should be like Edge because it's currently hard to work with it when a tab can't join another window unless that window is visible.

https://github.com/microsoft/terminal/assets/118815227/195417e9-0034-400b-bcf4-813d8f264563

Start with the four tasks in the issue and compare the linked video with Microsoft Edge's tab behavior. Confirm the required WinUI TabView v3 dependency before beginning; the work is done when tear-out, snapping, multi-tab drag/drop, and single-tab window dragging match the listed expectations.

Written by the indexing model from the issue text.