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/enterprise.go

@@ -50,12 +50,6 @@ func RegisterJobsElasticsearchIndexerInterface(f func(*Server) ejobs.IndexerJobI
 	jobsElasticsearchIndexerInterface = f
 }
 
-var jobsElasticsearchFixChannelIndexInterface func(*Server) ejobs.ElasticsearchFixChannelIndexInterface
-
-func RegisterJobsElasticsearchFixChannelIndexInterface(f func(*Server) ejobs.ElasticsearchFixChannelIndexInterface) {
-	jobsElasticsearchFixChannelIndexInterface = f
-}
-
 var jobsLdapSyncInterface func(*App) ejobs.LdapSyncInterface
 
 func RegisterJobsLdapSyncInterface(f func(*App) ejobs.LdapSyncInterface) {