Migrate Update method from ChannelStore to return idiomatic plain error (#14687)

* Partial advances

* Update migrated

* Fix imports

* Suggestions

* Suggestions

* Updating i18n

Co-authored-by: Jesús Espino <jespinog@gmail.com>
Co-authored-by: mattermod <mattermod@users.noreply.github.com>

store/timer_layer.go

@@ -1729,7 +1729,7 @@ func (s *TimerLayerChannelStore) SetDeleteAt(channelId string, deleteAt int64, u
 	return resultVar0
 }
 
-func (s *TimerLayerChannelStore) Update(channel *model.Channel) (*model.Channel, *model.AppError) {
+func (s *TimerLayerChannelStore) Update(channel *model.Channel) (*model.Channel, error) {
 	start := timemodule.Now()
 
 	resultVar0, resultVar1 := s.ChannelStore.Update(channel)