A Pallet for Benchmarking Common Runtime Operations (#4902)

* Benchmark pallet

* Add a bunch more benchmarks

* do nothing test

* new benchmarks

* Clean up extra tests

* Encode and Decode Vec<T::AccountId>

* Starting to migrate benchmarks to macro

* Use macro

* Remove call and storage

* Update Cargo.toml

* Add storage recalc benchmark

* Add support for custom functions in benchmark! macro

* Reset DB for storage recalc

* Feedback from review

* Add more comments

* Remove benchmark pallet from node

* Fix cargo files

* Fix comments

* Change `crate` to `super`

* missed one

* Use results of benchmark encode/decode

* Pass generic to extra functions

* reset macro to master

* Update lib.rs

* Update to use standard syntax