refactor: Move the tracking model into commons

common/models/tracker.ts

@@ -0,0 +1,16 @@
+export enum TrackerEvent {
+    LOG_IN = "LOG_IN",
+    LOG_OUT = "LOG_OUT",
+    START_LEARNING = "START_LEARNING",
+    CANCEL_LEARNING = "CANCEL_LEARNING",
+    FINISH_LEARNING = "FINISH_LEARNING",
+};
+
+export interface ITrackerRequest {
+    session: string;
+    event: TrackerEvent;
+};
+
+export type ITrackerDBModel = ITrackerRequest & {
+    timestamp: number;
+};