`RmrkCore::change_collection_issuer` unable to be applied to ink! contracts

[boyswan]

RmrkCore::change_collection_issuer requires permission in order to accept ownership - set_accept_ownership via the Uniques pallet.

A chain-extension exposing Uniques::set_accept_ownership is required in order for an ink! contract to be able to call this function.

[shunsukew]

Yes, uniques chain extension is required. @Maar-io Do you know if some teams started working on its implementation?