Describe the feature
Adding an inverter card into the card slot when configuring fluid storage would invert the storage configuration from the default whitelist to blacklist behaviour.

Reasons why it should be considered
Storage cells allow this functionality. (Fuzzy cards, however, are a little redundant in fluid storage, unless that would facilitate compat)
Intuition and consistency with the above.

Additional Context
This is using rv6 stable-6; however there was no mention of this in the changelog/commit history.
Inverter card displayed compatibility

I was trying to set up a water/NOT water pair of fluid cells, only to realise that the inverter card is incompatible. It is understandable that the current implementation requires some creativity in importing infinite water sources, but doesn't seem intuitive when next to the item storage and cobble gens!