cumulus test runtime: remove `GenesisExt` (#2147)
This PR removes the `GenesisExt` wrapper over the `GenesisRuntimeConfig`
in `cumulus-test-service`. Initialization of values that were performed
by `GenesisExt::BuildStorage` was moved into `test_pallet` genesis.
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Co-authored-by: command-bot <>
Co-authored-by: Bastian Köcher <[email protected]>