* Don't include `:code` by default in storage proofs (#5060)

* Adds test to verify that the runtime currently is always contained in
the proof

* Start passing the runtime wasm code from the outside

* Fix compilation

* More build fixes

* Make the test work as expected now :)

* Last fixes

* Fixes benchmarks

* Review feedback

* Apply suggestions from code review

Co-Authored-By: Sergei Pepyakin <sergei@parity.io>

* Review feedback

* Fix compilation

Co-authored-by: Sergei Pepyakin <s.pepyakin@gmail.com>

* Fix compilation and change the way `RuntimeCode` works

* Fix tests

* Switch to `Cow`

Co-authored-by: Benjamin Kampmann <ben@gnunicorn.org>
Co-authored-by: Sergei Pepyakin <s.pepyakin@gmail.com>