sp-api: Move macro related re-exports to __private (#2446)

This moves the macro related re-exports to `__private` to make it more
obvious for downstream users that they are using an internal api.

---------

Co-authored-by: command-bot <>

substrate/client/tracing/Cargo.toml

@@ -16,6 +16,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 ansi_term = "0.12.1"
 atty = "0.2.13"
 chrono = "0.4.27"
+codec = { package = "parity-scale-codec", version = "3.6.1" }
 lazy_static = "1.4.0"
 libc = "0.2.121"
 log = { version = "0.4.17" }

substrate/client/tracing/src/block/mod.rs

@@ -25,6 +25,7 @@ use std::{
 	time::Instant,
 };
 
+use codec::Encode;
 use parking_lot::Mutex;
 use tracing::{
 	dispatcher,
@@ -34,7 +35,7 @@ use tracing::{
 
 use crate::{SpanDatum, TraceEvent, Values};
 use sc_client_api::BlockBackend;
-use sp_api::{Core, Encode, Metadata, ProvideRuntimeApi};
+use sp_api::{Core, Metadata, ProvideRuntimeApi};
 use sp_blockchain::HeaderBackend;
 use sp_core::hexdisplay::HexDisplay;
 use sp_rpc::tracing::{BlockTrace, Span, TraceBlockResponse};