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/network/src/test/mod.rs

@@ -27,12 +27,13 @@ use std::sync::Arc;
 use crate::config::build_multiaddr;
 use log::trace;
 use crate::chain::FinalityProofProvider;
+use sp_blockchain::{
+	Result as ClientResult, well_known_cache_keys::{self, Id as CacheKeyId},
+};
 use client_api::{
 	ClientInfo, BlockchainEvents, BlockImportNotification,
 	FinalityNotifications, ImportNotifications,
 	FinalityNotification,
-	error::Result as ClientResult,
-	well_known_cache_keys::{self, Id as CacheKeyId},
 	backend::{AuxStore, Backend, Finalizer}
 };
 use block_builder::BlockBuilder;