Revert "feat(server): deprecated the subscription module."

This reverts commit 3b79ac66ae.

packages/server/src/services/Subscription/SubscriptionPeriod.ts

@@ -0,0 +1,41 @@
+import moment from 'moment';
+
+export default class SubscriptionPeriod {
+  start: Date;
+  end: Date;
+  interval: string;
+  count: number;
+
+  /**
+   * Constructor method.
+   * @param {string} interval -
+   * @param {number} count -
+   * @param {Date} start -
+   */
+  constructor(interval: string = 'month', count: number, start?: Date) {
+    this.interval = interval;
+    this.count = count;
+    this.start = start;
+
+    if (!start) {
+      this.start = moment().toDate();
+    }
+    this.end = moment(start).add(count, interval).toDate();
+  }
+
+  getStartDate() {
+    return this.start;
+  }
+
+  getEndDate() {
+    return this.end;
+  }
+
+  getInterval() {
+    return this.interval;
+  }
+
+  getIntervalCount() {
+    return this.interval;
+  }
+}