Add BEEFY capabilities to Westend and Kusama (#7591)

* runtime: add BEEFY and MMR to Westend

Signed-off-by: Adrian Catangiu <[email protected]>

* runtime: add BEEFY and MMR to Kusama

Signed-off-by: Adrian Catangiu <[email protected]>

* node/service: enable BEEFY for Westend and Kusama

Signed-off-by: Adrian Catangiu <[email protected]>

* node/service: regenerate genesis keys for westend-native and kusama-native

Since these keys are only used for development/local chains, also publish
the secret seeds used to generate the public keys, so that developers can
recover/generate the private key pairs if needed.

Signed-off-by: Adrian Catangiu <[email protected]>

* runtime: add session keys migration to add BEEFY to Westend and Kusama

* runtime: fix migration

* fix try-runtime build

* cargo fmt

* fix parachains slashing benchmark

* address review comments

* Apply suggestions from code review

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

* runtime: fix session keys migration

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Signed-off-by: Adrian Catangiu <[email protected]>
Co-authored-by: parity-processbot <>
Co-authored-by: Bastian Köcher <[email protected]>