feat: add reserve transfer example

[kratico]

Add reserve transfer asset example between Statemine and Trappist.

Notes

• for this example, Statemine acts as the source and reserve chain.
• the example uses trappist#22755b2 which is compatible with polkadot v0.9.37 and polkadot-parachain v0.9.370

The example steps are

• In Rococo, create a sufficient asset on Statemine (reserve parachain)
  Notes
  • asset should be sufficient to be able to pay fees in Statemine
  • root is needed to create a sufficient asset
  • in a common good parachains, root is accessed through the relay chain
• In Statemine, mint the new reserve asset
• In Trappist, create an asset to pair it with the Statemeine reserve asset
• In Trappist, register Trappist AssetId to Statemine AssetId
• In Statemine, make a reserve transfer asset to Trappist