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/bin/node-template/Cargo.toml

@@ -24,7 +24,7 @@ primitives = { package = "substrate-primitives", path = "../../primitives/core"
 substrate-executor = { path = "../../client/executor" }
 substrate-service = { path = "../../client/service" }
 inherents = { package = "substrate-inherents", path = "../../primitives/inherents" }
-transaction-pool = { package = "substrate-transaction-pool", path = "../../client/transaction-pool" }
+transaction-pool = { package = "sc-transaction-pool", path = "../../client/transaction-pool" }
 network = { package = "substrate-network", path = "../../client/network" }
 aura = { package = "substrate-consensus-aura", path = "../../client/consensus/aura" }
 aura-primitives = { package = "substrate-consensus-aura-primitives", path = "../../primitives/consensus/aura" }