Add config vars for perfect message and gerrit comments

Add the ability to configure message added by sputnik in gerrit for both comment and the former "Perfect !" message
I don't like we read ConfigurationHolder every time we need this format. Even more - I don't like that Review class relies heavily on ConfigurationHolder. It makes Review more coupled and complex.

I have one solution in mind. Create ProblemDTO and CommentDTO that contain only information. They can be formatted later.