BEEFY: Simplify hashing for pallet-beefy-mmr (#12393)

* beefy-mmr: reuse sp_runtime::traits::Keccak256

* beefy-mmr: use sp_runtime::traits:Hash for generating merkle proofs

* beefy-mmr: use sp_runtime::traits:Hash for validating merkle proofs

* beefy-mmr: remove primitives::Hasher and primitives::Hash

* fixes

* beefy-mmr: reduce the number of generic parameters for merkle_root()

* fix

* compute upper Vec capacity more accurately

frame/beefy-mmr/primitives/Cargo.toml

@@ -9,23 +9,22 @@ description = "A no-std/Substrate compatible library to construct binary merkle
 homepage = "https://substrate.io"
 
 [dependencies]
-hex = { version = "0.4", default-features = false, optional = true }
+array-bytes = { version = "4.1", optional = true }
 log = { version = "0.4", default-features = false, optional = true }
-tiny-keccak = { version = "2.0.2", features = ["keccak"], optional = true }
 
 beefy-primitives = { version = "4.0.0-dev", default-features = false, path = "../../../primitives/beefy" }
 sp-api = { version = "4.0.0-dev", default-features = false, path = "../../../primitives/api" }
+sp-runtime = { version = "6.0.0", default-features = false, path = "../../../primitives/runtime" }
 
 [dev-dependencies]
+array-bytes = "4.1"
 env_logger = "0.9"
-hex = "0.4"
-hex-literal = "0.3"
 
 [features]
-debug = ["hex", "hex/std", "log"]
-default = ["debug", "keccak", "std"]
-keccak = ["tiny-keccak"]
+debug = ["array-bytes", "log"]
+default = ["debug", "std"]
 std = [
 	"beefy-primitives/std",
-	"sp-api/std"
+	"sp-api/std",
+	"sp-runtime/std"
 ]