Add @Event documentation to all FieldStorageDefinitionEvents

This issue is for adding the @Event tag and appropriate documentation to the following list of events.

$this->eventDispatcher->dispatch(FieldStorageDefinitionEvents::CREATE, new FieldStorageDefinitionEvent($storage_definition));
$this->eventDispatcher->dispatch(FieldStorageDefinitionEvents::DELETE, new FieldStorageDefinitionEvent($storage_definition));
$this->eventDispatcher->dispatch(FieldStorageDefinitionEvents::UPDATE, new FieldStorageDefinitionEvent($storage_definition, $original));

This documentation should include the following information:

- What the event is
- What it is used for
- What kind of $event object is passed along.
- @see links to related classes (event class, representative class where event is dispatched, representative class where event is subscribed to).

See the parent issue for a documentation template, and more information: #2382169: [meta] Add @Event to all events defined by drupal core

Beta eval: This is API documentation, so unfrozen. Also very low disruption possibility.