Refine `CellInfo` type (#125351)

For #125269

- Rename `CellInfo` - >`OutputItem` (only internally, we also need to update the published types)
- Move `id` into `OutputItem`
- Move `element` out of `OutputItem`
- Rename `renderCell` to `renderOutputItem`
- Rename `destoryCell` to `disposeOutputItem` (`dispose` is  the term we generally use in our APIs)