Initial mechanics for 80:20 fee split (#2912)

* Initial mechanics for 80:20 fee split

Also:
- Introduce extra functions for Imbalance manipulation;
- Store treasury pot in an account, letting total issuance account for
  it.

* Fix some tests

* Fix some tests

* Minor cleanups

* Update parity-codec version (#2855)

* Update parity-codec version

* Update grandpa, rhododendron and trie-bench

* Use primitive-types from crates.io

* Bump impl version

* Fix trie-bench version

* Fix lock files

* Fix versions

* Update codec to 4.1

* merge fix

* Revert merge

* More reversions

* Remove accidental code

* Update locks

* Bump runtime

* Update locks

* Tweaks and label TODO

* Update srml/treasury/src/lib.rs

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* Update issue number

* Update core/sr-primitives/src/traits.rs

Co-Authored-By: Robert Habermeier <rphmeier@gmail.com>

* Fix wasm build

* Fix subkey build

substrate/node-template/runtime/wasm/Cargo.lock

@@ -2521,6 +2521,7 @@ dependencies = [
  "srml-metadata 2.0.0",
  "srml-support-procedural 2.0.0",
  "substrate-inherents 2.0.0",
+ "substrate-primitives 2.0.0",
 ]
 
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