Enable the database logging

Hey Valerio,

please find the intial working implementation of the database logs integration.

The following has been done:

- Middleware has been created in order to enable the databases events
- The config has been added, to allow for enabling / disabling the database logging
- Because of the config - the services (middleware and event subscriber) are conditionally added in the ServiceProvider, instead of services file (potentially we could do the cache clearing on submit of the form - now you need to do that manually)
- Segments started and ended on proper database events

There are a few caveats with this solution though. Database events can launch BEFORE the kernel event where you initialize the transaction. I had to do some magic with middleware and subscriber priorities to make sure the proper order is kept. The issue here is that with this configuration you lose a few queries (like a query to session table etc) that happen before the event where we initialize the transaction. I think, as a next step, we could move the transaction start to middleware, instead of event subscriber. If we can make the middleware run early - it should be fine.