IGNITE-13288 Mark activation and baseline events as internal.

[wirtsleg]

https://issues.apache.org/jira/browse/IGNITE-13288

Marked the following events as internal:

• EVT_CLUSTER_ACTIVATED
• EVT_CLUSTER_DEACTIVATED
• EVT_BASELINE_CHANGED
• EVT_CLUSTER_STATE_CHANGED

There are discovery events that are listened to by all nodes.
It will be useful to include these events to listen on all nodes by default too.
All of them are rare, system and cluster-wide.

[dmekhanikov]

I think we can make testClusterActivationEventsOnOtherNode more strict.
Something like this:

Ignite ignite_1 = startGrid(0);
Ignite ignite_2 = startGrid(1);

CountDownLatch deactivatedLatch = addDisposableLocalListener(ignite_2, EVT_CLUSTER_DEACTIVATED);
CountDownLatch stateChangedLatch1 = addDisposableLocalListener(ignite_2, EVT_CLUSTER_STATE_CHANGED);

ignite_1.cluster().state(ClusterState.INACTIVE);

assertTrue(deactivatedLatch.await(2, TimeUnit.SECONDS));
assertTrue(stateChangedLatch1.await(2, TimeUnit.SECONDS));

CountDownLatch activatedLatch = addDisposableLocalListener(ignite_2, EVT_CLUSTER_ACTIVATED);
CountDownLatch stateChangedLatch2 = addDisposableLocalListener(ignite_2, EVT_CLUSTER_STATE_CHANGED);

ignite_1.cluster().state(ClusterState.ACTIVE);

assertTrue(activatedLatch.await(2, TimeUnit.SECONDS));
assertTrue(stateChangedLatch2.await(2, TimeUnit.SECONDS));

Otherwise the fix looks good.