follow-chain testing mode for try-runtime (and revamp CLI configs). (#9788)

* deadlock, need to ask someone to help now

* Finally it seems to be working.. at least for a few blocks

* self-review

* major mega revamp

* some small fixes

* another mega refactor

* add license

* Apply suggestions from code review

* hack around signature verification

* Some fixes

* Update utils/frame/try-runtime/cli/src/lib.rs

Co-authored-by: Zeke Mostov <32168567+emostov@users.noreply.github.com>

* Update utils/frame/try-runtime/cli/src/lib.rs

Co-authored-by: Zeke Mostov <32168567+emostov@users.noreply.github.com>

* Update utils/frame/try-runtime/cli/src/lib.rs

Co-authored-by: Zeke Mostov <32168567+emostov@users.noreply.github.com>

* final tweaks, hopefully.

* a little self-review

* Add the ext root check

Co-authored-by: Zeke Mostov <32168567+emostov@users.noreply.github.com>

substrate/Cargo.lock

@@ -10687,6 +10687,7 @@ checksum = "59547bce71d9c38b83d9c0e92b6066c4253371f15005def0c30d9657f50c7642"
 name = "try-runtime-cli"
 version = "0.10.0-dev"
 dependencies = [
+ "jsonrpsee-ws-client",
  "log 0.4.14",
  "parity-scale-codec",
  "remote-externalities",
@@ -10696,9 +10697,12 @@ dependencies = [
  "sc-service",
  "serde",
  "sp-core",
+ "sp-externalities",
+ "sp-io",
  "sp-keystore",
  "sp-runtime",
  "sp-state-machine",
+ "sp-version",
  "structopt",
 ]