Removal of identity pallet and integration with ENS

[hackfisher]

With the launch of the Polkadot People Chain, Darwinia Chain follows Polkadot’s practice by removing the identity pallet from the runtime in release 6.6.4 . For details, please refer to https://forum.polkadot.network/t/people-chain-launch-and-identity-migration-plan/5930.

Regarding future identity integration plans, considering address compatibility and the fact that the Polkadot People Chain is still in its early stages and not yet fully mature, it is recommended to integrate directly with the already established ENS solution. For more details, please refer to: https://github.com/darwinia-network/collaboration/issues/61.