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/src/light/call_executor.rs

@@ -38,9 +38,10 @@ use hash_db::Hasher;
 
 use sr_api::{ProofRecorder, InitializeBlock};
 
+use sp_blockchain::{Error as ClientError, Result as ClientResult};
+
 use client_api::{
 	backend::RemoteBackend,
-	error::{Error as ClientError, Result as ClientResult},
 	light::RemoteCallRequest,
 	call_executor::CallExecutor
 };
@@ -450,7 +451,7 @@ mod tests {
 				),
 			);
 			match execution_result {
-				Err(client_api::error::Error::Execution(_)) => (),
+				Err(sp_blockchain::Error::Execution(_)) => (),
 				_ => panic!("Unexpected execution result: {:?}", execution_result),
 			}
 		}