[#146] Add ability to add comments to Michelson code

Description

Problem: it's not possible to add comment and get it printed among with code.

Solution: implement this feature.

The only issue I've came across: if a function ends with fail (usually it's getters with view, which usually ends with fail), commendAround theFunction function doesn't print the last comment "something: finished".

Related issue(s)

Resolves #146 (closed)

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