[Authorize upgrade] Upgrade authorization by Polkadot relay chain (#218)

* [Authorize upgrade] Draft scenario for initial testing

* [Authorize upgrade] Small fixes to make draft scenario to pass tests

* [Authorize upgrade] Polkadot network scenarios

* [Authorize upgrade] Remove some not relevant comments

Author: karolk91

README.md

@@ -209,8 +209,8 @@ permission-restricted extrinsics with the appropriate origin e.g. `Root`-gated g
 for staking and nomination pools
 
 4. **Send XCM `Transact`s to execute extrinsics with given origin in parachain**
-In parachains where `pallet-scheduler` is not available, but whose relay chain has it, use `xcmSendTransact` to
-perform the technique in 3. in the desired parachain.
+In parachains where `pallet-scheduler` is not available, but whose relay chain has it, use `createXcmTransactSend` 
+along with `scheduleCallWithOrigin` to prepare and schedule sending of an XCM to perform the technique in 3. in the desired parachain.
 
     4.1. Take care to adjust the parameters in accordance with the destination parachain, in particular
          `refTime/proofSize`