Add option to Query Log All Filter to log all matches to a single file

I ran into a situation recently where this ability might have been helpful to effectively have an equivalent to the MariaDB general query log via MaxScale. If this feature was added I'm certain I would use it. If this feature exists and I'm missing it, my apologies. I have experimented with enabling log_info to get the information I needed but even logging to a tmpfs MaxScale ran too slowly.