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/agent.js

@@ -1,5 +1,6 @@
 import { getAvailableAgents } from 'widget/api/agent';
 import * as MutationHelpers from 'shared/helpers/vuex/mutationHelpers';
+import { getFromCache, setCache } from 'shared/helpers/cache';
 
 const state = {
   records: [],
@@ -15,11 +16,22 @@ export const getters = {
     $state.records.filter(agent => agent.availability_status === 'online'),
 };
 
+const CACHE_KEY_PREFIX = 'chatwoot_available_agents_';
+
 export const actions = {
   fetchAvailableAgents: async ({ commit }, websiteToken) => {
     try {
+      const cachedData = getFromCache(`${CACHE_KEY_PREFIX}${websiteToken}`);
+      if (cachedData) {
+        commit('setAgents', cachedData);
+        commit('setError', false);
+        commit('setHasFetched', true);
+        return;
+      }
+
       const { data } = await getAvailableAgents(websiteToken);
       const { payload = [] } = data;
+      setCache(`${CACHE_KEY_PREFIX}${websiteToken}`, payload);
       commit('setAgents', payload);
       commit('setError', false);
       commit('setHasFetched', true);