write Helper contract to cover loss tests

[Zergity]

from main to simple, some tests have to be removed as the UTR is changed to be as simple as possible; any complex flow should be done in application's Helper or Adapter contracts

UTR changes:

• token will never, and should never be held in the UTR contract, even temporarily in the transaction. For any logic where tokens need to be held temporarily, application's Helper contracts are the recommended places to be used instead.
• removed: ALLOWANCE mode, anything *_FROM_ROUTER mode, action.flags, amountInSource
• amountInMax renamed to amountIn