allow try-runtime and TestExternalities to report PoV size (#10372)

* allow try-runtime and test-externalities to report proof size

* self review

* fix test

* Fix humanized dispaly of bytes

* Fix some test

* Fix some review grumbles

* last of the review comments

* fmt

* remove unused import

* move test

* fix import

* Update primitives/state-machine/src/testing.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* last touches

* fix

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/Cargo.lock

@@ -9650,6 +9650,7 @@ dependencies = [
  "sp-std",
  "sp-tracing",
  "substrate-test-runtime-client",
+ "zstd",
 ]
 
 [[package]]
@@ -10925,6 +10926,7 @@ dependencies = [
  "sp-state-machine",
  "sp-version",
  "structopt",
+ "zstd",
 ]
 
 [[package]]