MMR: move RPC code from frame/ to client/ (#12805)

* mmr: move MMR RPC from frame/ to client/

Signed-off-by: Adrian Catangiu <adrian@parity.io>

* client/mmr: adjust logging levels to avoid spam

* cargo fmt

* remove unused imports

Signed-off-by: Adrian Catangiu <adrian@parity.io>

substrate/Cargo.lock

@@ -4253,6 +4253,22 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "mmr-rpc"
+version = "4.0.0-dev"
+dependencies = [
+ "anyhow",
+ "jsonrpsee",
+ "parity-scale-codec",
+ "serde",
+ "serde_json",
+ "sp-api",
+ "sp-blockchain",
+ "sp-core",
+ "sp-mmr-primitives",
+ "sp-runtime",
+]
+
 [[package]]
 name = "mockall"
 version = "0.11.2"
@@ -4685,8 +4701,8 @@ name = "node-rpc"
 version = "3.0.0-dev"
 dependencies = [
  "jsonrpsee",
+ "mmr-rpc",
  "node-primitives",
- "pallet-mmr-rpc",
  "pallet-transaction-payment-rpc",
  "sc-chain-spec",
  "sc-client-api",
@@ -5682,22 +5698,6 @@ dependencies = [
  "sp-std",
 ]
 
-[[package]]
-name = "pallet-mmr-rpc"
-version = "3.0.0"
-dependencies = [
- "anyhow",
- "jsonrpsee",
- "parity-scale-codec",
- "serde",
- "serde_json",
- "sp-api",
- "sp-blockchain",
- "sp-core",
- "sp-mmr-primitives",
- "sp-runtime",
-]
-
 [[package]]
 name = "pallet-multisig"
 version = "4.0.0-dev"