Services: code style fixes, minor refactoring

What does this MR do?

It contains code style fixes, minor refactoring and also it removes some unnecessary comments. Every comment require a support just like a regular code line and this is why we should avoid using comments everywhere unless it's really helpful. Martin Fowler said "Find comment and refactor the code around it" :) our code is not that bad so let's not spoil it with comments.

Why was this MR needed?

Because GitLab is a live example of awesome code. Let's keep up a good job :)