Add logs to `smartcontracts/wasm.rs`

[Arjentix]

As @appetrosyan mentioned here we should consider adding some logs in this file

[Erigara]

@appetrosyan, what kind of behavior we want to log with debug?

If we are talking about errors during smartcontract execution, then we already log them inside functions that uses this module.

[mversic]

already fixed by @appetrosyan