Error Resistible Event interface

[Fedik]

Summary of Changes

A new interface, ErrorResistibleEventinterface, for error resistible events.
The event that implement this interface do not crash the dispatching process when an exception happening.
The dispatcher collect errors during this event, and gives it to the event for further handling.

This can help to solve issue for crashed system plugins in CMS. (In combination with joomla/joomla-cms#40522 and some update for exceptions handler.)

Testing Instructions

Test passes

Documentation Changes Required

A new feature.

[Fedik]

I have changed original implementation to be sure all errors is handled, and nothing gets "muted" by accident.

[Fedik]

Another way of doing it, would be on Dispatcher level (instead of fancy interface for events).
Have some kind of:

public Dispatcher::setErrorHandler(callable $handler)
private Dispatcher::handleEventError($event, $exception)

Thoughts?

[Fedik]

This will be better #35