TimeCounterEvent optimization

TimeCounterEvent in the Metrics module is now an abstract class, and events inherit from it to have the ability to calculate rt. Inheritance mechanism brings inflexibility and sometimes we have to inherit it in event generics. We can use composition pattern instead of inheritance

Start by locating TimeCounterEvent in the Metrics module and listing the event classes that inherit from it. Trace how those events calculate rt, then define completion as replacing the inheritance dependency with composition without losing that behavior.

Written by the indexing model from the issue text.