make remote ext use batch ws-client (#8916)

* make remote ext use batch ws-client

* Add debug log for key length

* better assertions

* new sanity_checl

* try and make it work with batch

* update test

* remove exctra uri

* add missing at

* remove unused rpc stuff

* improve

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

substrate/Cargo.lock

@@ -6678,11 +6678,14 @@ name = "remote-externalities"
 version = "0.9.0"
 dependencies = [
  "env_logger 0.8.3",
- "hex-literal",
+ "frame-support",
+ "hex",
  "jsonrpsee-proc-macros",
  "jsonrpsee-ws-client",
  "log",
+ "pallet-elections-phragmen",
  "parity-scale-codec",
+ "serde_json",
  "sp-core",
  "sp-io",
  "sp-runtime",