Reorganized structure, seperating implementations from core logic

pkg/data/events/mbpsnapshot.go

@@ -0,0 +1,13 @@
+package events
+
+type MBPSnapshot struct {
+	Bids  []PriceLevel
+	Asks  []PriceLevel
+	Depth int
+	Seq   uint64
+}
+
+type PriceLevel struct {
+	Price float64
+	Size  float64
+}