De-dup types early in CLI/macro so that derives/substitutes work for de-duped types (#2015)

* De-dup types early to enable derives for them

* ensure_unique_type_paths in CLI codegen, too

* Update UI test outpuot

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Co-authored-by: José Duarte <duarte.gmj@gmail.com>

testing/ui-tests/src/incorrect/substitute_at_wrong_path.stderr

@@ -11,9 +11,7 @@ error: Type `Event` does not exist at path `sp_runtime::multiaddress::Event`
        pallet_grandpa::pallet::Event
        pallet_treasury::pallet::Event
        pallet_conviction_voting::pallet::Event
-       pallet_referenda::pallet::Event
        pallet_ranked_collective::pallet::Event
-       pallet_referenda::pallet::Event
        pallet_whitelist::pallet::Event
        polkadot_runtime_common::claims::pallet::Event
        pallet_utility::pallet::Event