Added Scheduled Message event

pkg/message/scheduling/event.go

@@ -0,0 +1,15 @@
+package scheduling
+
+import (
+	"time"
+
+	"github.com/google/uuid"
+)
+
+type ScheduledEvent struct {
+	Id uuid.UUID `json:"id"`
+	RecipientId uuid.UUID `json:"recipient_id"`
+	MessageId uuid.UUID `json:"message_id"`
+	ScheduledMessageId uuid.UUID `json:"scheduled_message_id"`
+	Created time.Time `json:"created"`
+}