Merkle Mountain Range pallet improvements (#7891)

* Add stateless verification helper function.

* Split MMR primitives.

* Add RuntimeAPI

* RuntimeAPI with OpaqueLeaves

* Bump spec_version,.

* Move primitives back to frame.

* Fix OpaqueLeaf encoding.

* Add block number to frame_system implementation of LeafDataProvider.

* Relax leaf codec requirements and fix OpaqueLeaf

* Add root to debug line.

* Apply suggestions from code review

Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>

* Typo.

Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>

substrate/Cargo.lock

@@ -4741,6 +4741,7 @@ dependencies = [
  "frame-support",
  "frame-system",
  "hex-literal",
+ "pallet-mmr-primitives",
  "parity-scale-codec",
  "serde",
  "sp-core",
@@ -4749,6 +4750,21 @@ dependencies = [
  "sp-std",
 ]
 
+[[package]]
+name = "pallet-mmr-primitives"
+version = "2.0.0"
+dependencies = [
+ "frame-support",
+ "frame-system",
+ "hex-literal",
+ "parity-scale-codec",
+ "serde",
+ "sp-api",
+ "sp-core",
+ "sp-runtime",
+ "sp-std",
+]
+
 [[package]]
 name = "pallet-multisig"
 version = "2.0.1"