Rebuild channel index (#26080)

* WIP

* Added rebuild channels index functionality

* Added rough logic to send message to all sysadmins

* WIP

* WIP

* WIP

* Cleanup

* i18n fix

* reading through all pages of system admins

* Fixed webapp style

* i18n fix

* Added help text

* i18n fix

* i18n update

* Updated system console button action

* Updated snapshots

* some cleanup

* Updated snapshot

* Update server/channels/app/server.go

Co-authored-by: Daniel Espino García <larkox@gmail.com>

* fixed typo

* Refactoring to improve readibility

* moved index check to API later during config update

* Added some docs

* Updated get system bot

---------

Co-authored-by: Daniel Espino García <larkox@gmail.com>

webapp/platform/client/src/client4.ts

@@ -3369,9 +3369,9 @@ export default class Client4 {
         );
     };
 
-    purgeElasticsearchIndexes = () => {
+    purgeElasticsearchIndexes = (indexes?: string[]) => {
         return this.doFetch<StatusOK>(
-            `${this.getBaseRoute()}/elasticsearch/purge_indexes`,
+            `${this.getBaseRoute()}/elasticsearch/purge_indexes${indexes && indexes.length > 0 ? '?index=' + indexes.join(',') : ''}`,
             {method: 'post'},
         );
     };