This replaces the `otelevents.enabled` property.
With this change, every property does exactly one thing:
- `sumologic.events.enabled` enables or disables events collection
- `sumologic.events.provider` switches between Fluentd and Otelcol
We also still support the (now deprecated) `fluentd.events.enabled`
property to disable events collection with Fluentd.

The tests were using the undocumented and nonexisting `sumologic.events.enabled` property
in a way that collided with the changes to events configuration.

Changing the number of expected endpoints created from 2 to 1,
because the events endpoint is no longer being created
when events are disabled.

It took me a good while to find the cause of the failures.
Hopefully the additional comments will make it easier.