Add more automation for breaking provider changes

We should add more automation about classifying changes for providers and notifying RM about breaking changes.

There are few options to consider:

* implemneting newsfragment workflows (separate set of newsfragments for providers)
* using conventional commits (optional fot type of event mandatory for BREAKING CHANGES)

What we can achieve by that:

* contributor will never edit changelog - even if there is a breaking change
* changelog will only be modified by RM during "prepare providers documentation"
* there is less work for RM to classify commits if type of the change can be derived from the extra metadata - either in newsfragments or in conventional commit

### Newsfragments:

Pros:
* the workflow resembles the one used in airflow (however we would not use selective cherry-picking)

Cons:
* quite a bit more complicated and involved workflows

### Conventional commits:

Pros:
* simple for contributors - all you need is adding ! in commit subject or adding BREAKING CHANGE in the commit message

Cons:
* we generally do not like conventional commits as they look prety ugly with git log and take precious space of the message.
* cross provider commits might have different classification

I think we shoudl discuss among release managers and get devlist discussion - which option to choose before we start implementing it.