Restructure omni services and add Chatwoot research snapshot

research/chatwoot/app/javascript/dashboard/api/assignableAgents.js

@@ -0,0 +1,16 @@
+/* global axios */
+import ApiClient from './ApiClient';
+
+class AssignableAgents extends ApiClient {
+  constructor() {
+    super('assignable_agents', { accountScoped: true });
+  }
+
+  get(inboxIds) {
+    return axios.get(this.url, {
+      params: { inbox_ids: inboxIds },
+    });
+  }
+}
+
+export default new AssignableAgents();