Allow reserve asset transfer of relaychain token to parachain and back

[brenzi]

first step to bring TEER to Asset Hub is to bring KSM to Integritee (to pay xcm fees with)

This PR allows to

• reserve asset transfer KSM from relaychain to Integritee
• reserve asset transfer KSM from integritee to relaychain

the chosen solutions are inspired from Karura and Trappist

• add orml_tokens (but don't expose its dispatchables)
• add orml_currencies
• modify XCM Barrier
• modify XCM Trader

sanity checks:

• tokens are hardcoded. only runtime-upgrade can add more fungible tokens
• currencies.updateBalance yields BadOrigin for users

do not merge just yet

This PR makes a design decision that we may want to iterate on!

• use orml pallets instead of polkadot-sdk pallet_assets because the latter is more generic and powerful than necessary
• hard-code all assets and mappings to MultiLocation
  • this may cause more work in the future, if we would like to maintain the single-runtime for Kusama and Polkadot policy
  • also causes more maintance work (should we decide to host USDC/USDT as well

testing

start zombienet

zombienet-linux-x64 spawn --provider native zombienet/rococo-local-with-integritee.toml

send 1 ROC from relaychain to integritee network

0x6308030001007d1f0300010100d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d030400000000070010a5d4e80000000000

you should see tokens.Deposited Event on Integritee Network

check balance:

send funds from Alice to Bob

send ROC back from Bob to Bob on relaychain

[brenzi]

orml_tokens / orml_currencies do not implement AccountTouch nor ContainsPair traits which are needed for pallet_asset_conversion

I guess the decision to use ORML for this was wrong