feat(events): added CSI style events package

Author: shanduur

Diff for: controller/events/events.go

@@ -0,0 +1,10 @@
+package events
+
+// COSI relevant event reasons
+const (
+	BucketDeleteFailed   = "BucketDeleteFailed"
+	GrantingAccessFailed = "GrantingAccessFailed"
+	ProvisioningFailed   = "ProvisioningFailed"
+	RevokingAccessFailed = "RevokingAccessFailed"
+	WaitingForBucket     = "WaitingForBucket"
+)