add pallet nomination-pools versioned migration to kitchensink (#2167)

The versioned migrations are already there in pallet nomination-pools:

https://github.com/paritytech/polkadot-sdk/blob/f6ee4781f633f0f89598f7b230595afe401da8dc/substrate/frame/nomination-pools/src/migration.rs#L27-L48

Just updating the kitchensink runtime to point to them.

This is also nice because it points the dev to an example of how to use
`VersionedMigration`.