Smart Contracts: trigger datetime should be rounded to the minute.

[bchamagne]

Describe the problem you discovered

With current datetime worflow, there is a possibility for a contract to run every second.
We must handle this case by rounding the datetime to the closest minute.

Describe the solution you'd like

No response

Additional context

Epic: #608

[samuelmanzanera]

We could probably check in the interpreter parser than the timestamp should not include second (only 0s) . Hence the timestamp would always be minute based.