state_machine no_std witness externalities (#6934)

* checkpoint before removing CT from change trie

* before trie backend without tx

* undo

* Started no transaction, but would need using a different root
calculation method, out of the scope of this pr, will roll back.

* Remove NoTransaction.

* partially address review.
dummy stats implementation for no_std.

* Remove ChangeTrieOverlay.

* modified function

* Remove witness_ext

* need noops changes root

* update from cumulus branch

* line break

* remove warning

* line break

* From review: renamings and stats active in no std (except time).

* include cache, exclude change trie cache with individual temporary bad looking
no_std check

* little test

* fuse imports and filter_map prepare_extrinsics_input_inner fold.

* put back ExtInner into Ext, awkward double proto for new function.

* Apply suggestions from code review

* Update primitives/state-machine/Cargo.toml

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

substrate/Cargo.lock

@@ -8424,7 +8424,6 @@ version = "0.8.0-rc6"
 dependencies = [
  "hash-db",
  "hex-literal",
- "itertools 0.9.0",
  "log",
  "num-traits",
  "parity-scale-codec",
@@ -8436,6 +8435,7 @@ dependencies = [
  "sp-externalities",
  "sp-panic-handler",
  "sp-runtime",
+ "sp-std",
  "sp-trie",
  "trie-db",
  "trie-root",
@@ -8833,6 +8833,7 @@ dependencies = [
  "sp-consensus-aura",
  "sp-consensus-babe",
  "sp-core",
+ "sp-externalities",
  "sp-finality-grandpa",
  "sp-inherents",
  "sp-io",