Cleanup Repository & Fix CI (#211)

* Move all scripts to a single directory

* Switch to cargo-make

* Remove the polkadot-sdk from the submodules

* WIP: update the CI

* Add other jobs to CI

* Overhaul the polkadot-sdk caching step

* Add a testing step

* Fix the CI

* Install clang and llvm dependencies

* Update the version of clang

* Install llvm on macos

* Fix ci

* Fix ci

* Use 1.90.0 version of rust for the polkadot-sdk

* Fix CI

* Fix CI

* Fix CI

* Fix CI

* Fix CI

* Allow warnings

* Update runners

* Update runners

* Simplify CI

* Update MacOS runner

* Fix zombienet tests

* Make cache step faster

.gitmodules

@@ -1,6 +1,3 @@
-[submodule "polkadot-sdk"]
-	path = polkadot-sdk
-	url = https://github.com/paritytech/polkadot-sdk.git
 [submodule "resolc-compiler-tests"]
 	path = resolc-compiler-tests
 	url = https://github.com/paritytech/resolc-compiler-tests