Metrics performance improvements

[konraddysput]

Why

Attribute generations .... cost us time. We generated them multiple times during metrics setup AND metrics payload generation. In addition to that we had a situation where we generated attributes twice during single object creation (in the constructor to get an application name and later to get all attributes for payload)

This pull request significantly improves the performance of the metrics system - my internal results give me 2x time reduction. Other parts of our system can also benefit from it - everything that uses our attribute system should retrieve results faster.

ref: BT-2660

[BartoszLitwiniuk]

to be honest I really don't like introducing tuples because of

• lack of Readability and self-Documentation
• weak type safety
• java's type system is designed for strongly-typed, structured objects rather than lightweight, anonymous data structures like tuples
• if we wanted to add another field/attribute you will introduce Triplet? so it is much more difficult to develop and modify later

It's easier just to wrap two fields with small object and pass it together if they are logically combined, if not then maybe code is bad designed.

[BartoszLitwiniuk]

lgtm