companion PR for https://github.com/paritytech/substrate/pull/13373 (#2547)

* companion PR for https://github.com/paritytech/substrate/pull/13373

* Add missing trait function

* Fix template

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Add missing weight functions

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* update lockfile for {"polkadot", "substrate"}

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Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Falco Hirschenberger <falco.hirschenberger@itwm.fraunhofer.de>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: parity-processbot <>