Remove all (non-dev) client references from frame, activate dependency enforcer (#4184)

* Move transaction pool to primitives

* move backend, errors into primitives

* remove unused client depencies

* Move rpc-api into primitives

* Move peerset back to client

* Move rpc/api back to client, move palette/support/rpc into utils

* move support-rpc into subfolder

* move system-rpc into utils

* move transaction-pool  and -graph back into client

* fix broken imports

* Clean up test primitives

* Make support test utils independent of frame

* remove unnecessary node dependencies from service

* Reactivate dependency script:
 - only enforce the now achieved status quo will remain
 - allow for primitives to depend on /client for now without failing
 - more discriptive error message so people understand, what it wants
 - minor fix to differentiative between ../client and /client (which may be a subfolder)
 - don't allow this to fail anylonger.

* fix doc comment

* 'Should not' rather than 'must not'.

* Revert unwanted dependency changes

* fix faulty import

* fixup derive_more version

* fix wrong import path

substrate/client/finality-grandpa/src/finality_proof.rs

@@ -38,11 +38,10 @@ use std::iter;
 use std::sync::Arc;
 use log::{trace, warn};
 
+use sp_blockchain::{Backend as BlockchainBackend, Error as ClientError, Result as ClientResult};
 use client_api::{
-	backend::Backend, blockchain::Backend as BlockchainBackend, CallExecutor,
-	error::{Error as ClientError, Result as ClientResult},
+	backend::Backend, CallExecutor, StorageProof,
 	light::{FetchChecker, RemoteReadRequest},
-	StorageProof,
 };
 use client::Client;
 use codec::{Encode, Decode};
@@ -259,7 +258,7 @@ pub(crate) fn prove_finality<Block: BlockT<Hash=H256>, B: BlockchainBackend<Bloc
 	authorities_set_id: u64,
 	begin: Block::Hash,
 	end: Block::Hash,
-) -> ::client_api::error::Result<Option<Vec<u8>>>
+) -> ::sp_blockchain::Result<Option<Vec<u8>>>
 	where
 		J: ProvableJustification<Block::Header>,
 {