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>

server/channels/app/server.go

@@ -490,6 +490,8 @@ func NewServer(options ...Option) (*Server, error) {
 		}
 	})
 
+	app.initElasticsearchChannelIndexCheck()
+
 	return s, nil
 }
 
@@ -1479,11 +1481,6 @@ func (s *Server) initJobs() {
 		s.Jobs.RegisterJobType(model.JobTypeElasticsearchPostIndexing, builder.MakeWorker(), nil)
 	}
 
-	if jobsElasticsearchFixChannelIndexInterface != nil {
-		builder := jobsElasticsearchFixChannelIndexInterface(s)
-		s.Jobs.RegisterJobType(model.JobTypeElasticsearchFixChannelIndex, builder.MakeWorker(), nil)
-	}
-
 	if jobsLdapSyncInterface != nil {
 		builder := jobsLdapSyncInterface(New(ServerConnector(s.Channels())))
 		s.Jobs.RegisterJobType(model.JobTypeLdapSync, builder.MakeWorker(), builder.MakeScheduler())