Due to the need to make all the different NC isotopes meltable for stabilizing, some additional fluids were added via ContentTweaker, like liquid Plutonium. While this is fine in most cases, there are a few recipes which block players from certain avenues of making things like plates.

Currently for example Plutonium 241 extracts into the ContentTweaker Plutonium fluid rather than GTCE's Plutonium 241 fluid. This means it is impossible to solidify into blocks so you can use a Cutting Machine to produce plates, or even solidify directly into plates.

While this isn't a huge problem for that specific material (as only the Fusion Reactor Mk1 recipe uses it), it diverges from how isotope fluids are handled for things like Uranium 235 and 238, where the corresponding GTCE isotope fluid is used, and Uranium 233, where GTCE has no equivalent and a ContentTweaker fluid is added.

We need to ensure that we consistently handle fluid extraction for isotopes like we do for Uranium to not prevent players from accessing certain routes to making items.

In short:

• Wherever a GTCE fluid form of an isotope exists, fluid extraction of solid forms of that isotope must produce that fluid, and a ball mold recipe to turn that fluid into stabilized in the same ratios as any corresponding ContentTweaker fluid must be added.
• Wherever no corresponding GTCE fluid of an isotope exists, fluid extraction must produce a unifying ContentTweaker fluid whose sole purpose is producing stabilized isotope items via a ball mold.

This is now somewhat duplicative of #587, which spells out in a table how exactly we want the fluids to work. Gonna link it to the PR as well.