Add multiple tiers aggregaion to DORA API

What does this MR do and why?

It adds new API param which allows to gather aggregated information for multiple environment tiers combined. Deprecation issue for old param is here.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #348577 (closed)

Edited by Pavel Shutsin