Add proper condition checks to the interation with the blockchain (using Raiden proxies)

[hackaugusto]

Description

Scenario failures messages are useless, example:

scenario_player.exceptions.legacy.ScenarioTxError: Transaction 0x4f26e8b4d9cbeb06fe339ff85f6f4140a8e63be4d76475975f9bd3e104cb1915 failed.

Expected Behavior

The asserts/requires of a smart contract should be verified before and after a transaction is sent, and a proper error message should be given. The above error message is not useful for a user and it takes a long time to debug.

Please consider using the proxies from the raiden package, a lot of time was spent making sure these messages are useful, and that all cases are properly covered. e.g. The above error is likely handled by this code