PLT-6019: Add APIv4 Endpoint for restoring Channels (#6263)

store/store.go

@@ -97,6 +97,7 @@ type ChannelStore interface {
 	InvalidateChannelByName(teamId, name string)
 	GetFromMaster(id string) StoreChannel
 	Delete(channelId string, time int64) StoreChannel
+	Restore(channelId string, time int64) StoreChannel
 	SetDeleteAt(channelId string, deleteAt int64, updateAt int64) StoreChannel
 	PermanentDeleteByTeam(teamId string) StoreChannel
 	PermanentDelete(channelId string) StoreChannel