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/lib.rs

@@ -18,20 +18,17 @@
 #![warn(missing_docs)]
 
 pub mod backend;
-pub mod blockchain;
 pub mod call_executor;
 pub mod client;
-pub mod error;
 pub mod execution_extensions;
 pub mod light;
 pub mod notifications;
 
-// TODO: avoid re-exports
+pub use sp_blockchain as blockchain;
 pub use backend::*;
-pub use blockchain::*;
+pub use notifications::*;
 pub use call_executor::*;
 pub use client::*;
-pub use error::*;
 pub use light::*;
 pub use notifications::*;
 
@@ -40,9 +37,7 @@ pub use state_machine::{StorageProof, ExecutionStrategy};
 
 /// Utility methods for the client.
 pub mod utils {
-    use super::HeaderBackend;
-    use header_metadata::HeaderMetadata;
-	use crate::error;
+    use sp_blockchain::{HeaderBackend, HeaderMetadata, Error};
     use primitives::H256;
 	use sr_primitives::traits::{Block as BlockT};
 	use std::borrow::Borrow;
@@ -56,8 +51,8 @@ pub mod utils {
 	pub fn is_descendent_of<'a, Block: BlockT<Hash=H256>, T, H: Borrow<H256> + 'a>(
 		client: &'a T,
 		current: Option<(H, H)>,
-	) -> impl Fn(&H256, &H256) -> Result<bool, error::Error> + 'a
-		where T: HeaderBackend<Block> + HeaderMetadata<Block, Error=error::Error>,
+	) -> impl Fn(&H256, &H256) -> Result<bool, Error> + 'a
+		where T: HeaderBackend<Block> + HeaderMetadata<Block, Error=Error>,
 	{
 		move |base, hash| {
 			if base == hash { return Ok(false); }
@@ -76,7 +71,7 @@ pub mod utils {
 				}
 			}
 
-			let ancestor = header_metadata::lowest_common_ancestor(client, *hash, *base)?;
+			let ancestor = sp_blockchain::lowest_common_ancestor(client, *hash, *base)?;
 
 			Ok(ancestor.hash == *base)
 		}