Remove the `Copy` bound on `AssetId` (#14158)

* Remove the `Copy` bound on `AssetId`

* Also relax the `Copy` bound in the assets pallet

* Fix warnings on the newest nightly Rust

* Remove some unnecessary `clone()`s

* Try to satisfy clippy

* Remove some more unnecessary `clone()`s

* Add more `.clone()`s for newly merged code

* Also add `clone()`s in the benchmarks

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Co-authored-by: parity-processbot <>