Apply TPPI Big Reactor Tweaks

From https://github.com/TPPI-Dev/TestPackPleaseIgnore2/blob/868e3bf7bbb9d5c78a8428346f31bf56a106ddea/config/BigReactors/BigReactors.cfg

- Removes cross-registration of yellorium and Uranium.  If we want this back, it's just registration, not worldgen.
- Removes charcoal/coal smelting to graphite recipes.
- Tweaks BR power generation.  If we think this is too much, we'll pull back a bit on the numbers.