Rebalance personal fusion cells.

[kyran-z]

To streamline personal fusion cells to the other kinds of batteries in the game (nexelite and quantum ones, bio-batteries don't count since they don't have a spent form), though I realize this is a breaking change.
-> The current personal fusion cell recipe should produce a spent cell instead of a normal one
-> Remove the cost of tritium and deuterium in the recipe, as they're the "fuel", like the nexelite plate and the thorium for the other batteries. This means that after producing a spent cell you need to charge it, the final cost would be unchanged.
-> (optional) Allow productivity to the recipe (like the quantum ones and tbh, even the nexelite batteries should allow it)