* Remove entirely the hook priority numbers and use before/after dependencies
* Split the WpEvent code out of WpEventDispatcher
* Add methods on WpEvent to interface with it from the WpEventDispatcher.
As a bonus, we can now also implement tooling to inspect which hooks would
in theory run for an event and write tests around that
* Removed some internal debugging facilities and log calls, will redo it later.
* Using spa_list now for the list of hooks, to reduce the number of allocations
happening in the "hook collection" algorithm
* Switched some internal data to use g_new0 instead of g_slice_new0
* Added g_free to free WpEvent structures... surprisingly, we were leaking them
before
- Add a new variable "name" in WpEventHook and use it to log all the
hooks(by name) picked up in _push_event(). This gives a clear picture
if hook is registered for a given event.
- Form a name for an event and a chain of events for an event run, log
both of them. This gives a clear picture of the events executed and
order in which they are dispatched.
- Similarly build hooks chain and print it in _source_dispatch(), this
gives a clear picture of the hooks picked and the order in which they
are dispatched.
- Log only the dispatchable(with hooks) events, this de-clutters
the log messages.
