Remove usage of substrate-test-runtime. (#969)

* Switch from using the substrate_test_runtime Extrinsic to the polkadot_test_runtime one

* Copy genesismap into test-runtime

* Add UncheckedExtrinsics

* Fix tests :^)

* Remove unused functions from genesismap

* DRY, clean up

* Clean up

* Update service/src/grandpa_support.rs

Co-Authored-By: Bastian Köcher <[email protected]>

* Fix indentation

* Update runtime/test-runtime/src/genesismap.rs

Co-authored-by: Bastian Köcher <[email protected]>