Expose MMR root through runtime API - use it in BEEFY client (#11183)

* beefy-gadget: allow custom runtime api provider

* beefy-gadget: use mock runtime api in tests

* pallet-mmr: expose mmr root from state through runtime API

* beefy-gadget: get mmr root from runtime state

* pallet-beefy-mmr: remove MmrRoot from header digests

* frame/mmr: move mmr primitives out of frame

* frame/mmr: completely move primitives out of frame

* address review comments

* beefy-mmr: bring back mmr root from header digest

* clippy fixes for rustc 1.60

* address review comments

substrate/primitives/merkle-mountain-range/Cargo.toml

@@ -0,0 +1,39 @@
+[package]
+name = "sp-mmr-primitives"
+version = "4.0.0-dev"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2021"
+license = "Apache-2.0"
+homepage = "https://substrate.io"
+repository = "https://github.com/paritytech/substrate/"
+description = "Merkle Mountain Range primitives."
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.0.0", default-features = false }
+log = { version = "0.4.14", default-features = false }
+serde = { version = "1.0.136", optional = true, features = ["derive"] }
+
+sp-api = { version = "4.0.0-dev", default-features = false, path = "../api" }
+sp-core = { version = "6.0.0", default-features = false, path = "../core" }
+sp-debug-derive = { version = "4.0.0", default-features = false, path = "../debug-derive" }
+sp-runtime = { version = "6.0.0", default-features = false, path = "../runtime" }
+sp-std = { version = "4.0.0", default-features = false, path = "../std" }
+
+[dev-dependencies]
+hex-literal = "0.3"
+
+[features]
+default = ["std"]
+std = [
+	"codec/std",
+	"log/std",
+	"serde",
+	"sp-api/std",
+	"sp-core/std",
+	"sp-debug-derive/std",
+	"sp-runtime/std",
+	"sp-std/std",
+]