MM-8607 Add ability to turn off non-critical services when under load (#13212)

* MM-8607: add ability to turn off non-critical services under load

* server busy invalid param unit tests

* MM-8607: rename server busy endpoints

* MM-8607: handle case where App not initialized

* MM-8607: additional unit test cases per feedback.

* MM-8607: use decorator to check isbusy when adding endpoint route

* MM-8607: rename endpoints, use struct for json

* Update api4/system.go

Fix misspelled log output

Co-Authored-By: Saturnino Abril <saturnino.abril@gmail.com>

* MM-8607: fix i18n order; max seconds for server busy expiry

api4/team.go

@@ -34,7 +34,7 @@ func (api *API) InitTeam() {
 	api.BaseRoutes.Teams.Handle("", api.ApiSessionRequired(createTeam)).Methods("POST")
 	api.BaseRoutes.Teams.Handle("", api.ApiSessionRequired(getAllTeams)).Methods("GET")
 	api.BaseRoutes.Teams.Handle("/{team_id:[A-Za-z0-9]+}/scheme", api.ApiSessionRequired(updateTeamScheme)).Methods("PUT")
-	api.BaseRoutes.Teams.Handle("/search", api.ApiSessionRequired(searchTeams)).Methods("POST")
+	api.BaseRoutes.Teams.Handle("/search", api.ApiSessionRequiredDisableWhenBusy(searchTeams)).Methods("POST")
 	api.BaseRoutes.TeamsForUser.Handle("", api.ApiSessionRequired(getTeamsForUser)).Methods("GET")
 	api.BaseRoutes.TeamsForUser.Handle("/unread", api.ApiSessionRequired(getTeamsUnreadForUser)).Methods("GET")