Improve logging

[ademarco]

We should implement the following:

• Add debug level for parsing event
• Add sent response event for notification as info level

Also rename event classes as suggested on https://symfony.com/doc/current/components/event_dispatcher.html#naming-conventions

Naming Conventions
The unique event name can be any string, but optionally follows a few simple naming conventions:

Use only lowercase letters, numbers, dots (.) and underscores (_);
Prefix names with a namespace followed by a dot (e.g. order., user.*);
End names with a verb that indicates what action has been taken (e.g. order.placed).

[ademarco]

This is ready for review @netlooker @imanoleguskiza