Simplify AI Event classes by using base classes

I created two base classes:
- AiProviderRequestBaseEvent
- AiProviderResponseBaseEvent
that stores all the common properties and getters-setters for the child events - this allowed us to make the real event classes compact and almost empty: + 521 − 819 lines ;)

Moving the issue to needs review.

a.dmitriiev → made their first commit to this issue’s fork.

The idea is good and the implementation looks also fine. I have only one concern, please check the MR comment.

So, if the current implementation is okay, let's merge this then? Rebased on the fresh base branch, please make a fresh review.

It looks good now, but there is now problem in src/Base/OpenAiBasedProviderClientBase.php line 356, the setChatTokenUsage method expects second parameter to be array, but StreamedResponse object is passed. Maybe Marcus can check this?

Because of this error there is no way to test the Streamed logging.

Seems the problem was in the wrong order of parameters, I fixed this and reworked the code to use named parameters to minimize such errors in the future, take a look pls.