Companion PR for substrate PR 8072 - Add a config field to babe epochs (#2467)

* Add a config field to babe epochs

* Fix test

* Add BABE_GENESIS_EPOCH_CONFIG consts

* Use PrimaryAndSecondaryVRFSlots and remove newlines

* Make epoch_configs Some

* Fix tests

* Fix test service tests

* Add a BabeEpochConfigMigrations OnRuntimeUpgrade

* Apply suggestions

* Use PrimaryAndSecondaryPlainSlots in kusama

* Remove migration from test runtime and rococo

* Add HasPalletPrefix

* Rename to BabePalletPrefix and change BabeApi -> Babe

* "Update Substrate"

* Update substrate

* Resolve parantheses errors

Co-authored-by: parity-processbot <>