chore: Add cache to improve widget performance (#11163)

- Add dynamic importing for routes.
- Added caching for `campaign`, `articles` and `inbox_members` API end
points.

---------

Co-authored-by: Pranav <pranavrajs@gmail.com>

app/javascript/widget/store/modules/specs/campaign/actions.spec.js

@@ -1,10 +1,12 @@
 import { API } from 'widget/helpers/axios';
 import { actions } from '../../campaign';
 import { campaigns } from './data';
+import { getFromCache, setCache } from 'shared/helpers/cache';
 
 const commit = vi.fn();
 const dispatch = vi.fn();
 vi.mock('widget/helpers/axios');
+vi.mock('shared/helpers/cache');
 
 import campaignTimer from 'widget/helpers/campaignTimer';
 vi.mock('widget/helpers/campaignTimer', () => ({
@@ -15,8 +17,17 @@ vi.mock('widget/helpers/campaignTimer', () => ({
 
 describe('#actions', () => {
   describe('#fetchCampaigns', () => {
-    it('sends correct actions if API is success', async () => {
-      API.get.mockResolvedValue({ data: campaigns });
+    beforeEach(() => {
+      commit.mockClear();
+      getFromCache.mockClear();
+      setCache.mockClear();
+      API.get.mockClear();
+      campaignTimer.initTimers.mockClear();
+    });
+
+    it('uses cached data when available', async () => {
+      getFromCache.mockReturnValue(campaigns);
+
       await actions.fetchCampaigns(
         { commit },
         {
@@ -25,6 +36,54 @@ describe('#actions', () => {
           isInBusinessHours: true,
         }
       );
+
+      expect(getFromCache).toHaveBeenCalledWith(
+        'chatwoot_campaigns_XDsafmADasd',
+        60 * 60 * 1000
+      );
+      expect(API.get).not.toHaveBeenCalled();
+      expect(setCache).not.toHaveBeenCalled();
+      expect(commit.mock.calls).toEqual([
+        ['setCampaigns', campaigns],
+        ['setError', false],
+      ]);
+      expect(campaignTimer.initTimers).toHaveBeenCalledWith(
+        {
+          campaigns: [
+            {
+              id: 11,
+              timeOnPage: '20',
+              url: 'https://chatwoot.com',
+              triggerOnlyDuringBusinessHours: false,
+            },
+          ],
+        },
+        'XDsafmADasd'
+      );
+    });
+
+    it('fetches and caches data when cache is not available', async () => {
+      getFromCache.mockReturnValue(null);
+      API.get.mockResolvedValue({ data: campaigns });
+
+      await actions.fetchCampaigns(
+        { commit },
+        {
+          websiteToken: 'XDsafmADasd',
+          currentURL: 'https://chatwoot.com',
+          isInBusinessHours: true,
+        }
+      );
+
+      expect(getFromCache).toHaveBeenCalledWith(
+        'chatwoot_campaigns_XDsafmADasd',
+        60 * 60 * 1000
+      );
+      expect(API.get).toHaveBeenCalled();
+      expect(setCache).toHaveBeenCalledWith(
+        'chatwoot_campaigns_XDsafmADasd',
+        campaigns
+      );
       expect(commit.mock.calls).toEqual([
         ['setCampaigns', campaigns],
         ['setError', false],
@@ -43,7 +102,9 @@ describe('#actions', () => {
         'XDsafmADasd'
       );
     });
+
     it('sends correct actions if API is error', async () => {
+      getFromCache.mockReturnValue(null);
       API.get.mockRejectedValue({ message: 'Authentication required' });
       await actions.fetchCampaigns(
         { commit },