As per #3326, removes pallet::getter macro usage from the
pallet-identity. The syntax `StorageItem::<T, I>::get()` should be used
instead.

Also makes all storage values public

cc @muraca

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Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: command-bot <>