This PR introduces a new `NonFungibleAdapter`.

It will be useful for enabling cross-chain Coretime region transfers, as
the existing `NonFungiblesAdapter` is unsuitable for this purpose. This
is due to the fact that there is only one class of items within the
`pallet-broker`, i.e., the Coretime regions.

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Co-authored-by: Francisco Aguirre <[email protected]>
Co-authored-by: Dónal Murray <[email protected]>