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/api/src/light.rs

@@ -28,16 +28,11 @@ use sr_primitives::{
 };
 use primitives::{ChangesTrieConfiguration};
 use state_machine::StorageProof;
-use header_metadata::HeaderMetadata;
-use crate::{
-	backend::{
-		AuxStore, NewBlockState,
-	},
-    blockchain::{
-        well_known_cache_keys, HeaderBackend, Cache as BlockchainCache,
-    },
-    error::{ Error as ClientError, Result as ClientResult },
+use sp_blockchain::{
+	HeaderMetadata, well_known_cache_keys, HeaderBackend, Cache as BlockchainCache,
+	Error as ClientError, Result as ClientResult,
 };
+use crate::backend::{ AuxStore, NewBlockState };
 /// Remote call request.
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct RemoteCallRequest<Header: HeaderT> {
@@ -288,7 +283,7 @@ pub trait RemoteBlockchain<Block: BlockT>: Send + Sync {
 pub mod tests {
 	use futures::future::Ready;
 	use parking_lot::Mutex;
-    use crate::error::Error as ClientError;
+    use sp_blockchain::Error as ClientError;
     use test_primitives::{Block, Header, Extrinsic};
 	use super::*;