Tox dependency genes

Add some genes adding a pollution dependency to their carriers based on the genes from VRE Wasters
They reduce the carriers' breathing if they spend too much time outside of polluted area
These genes do not confer any protection against pollution and toxic buildup

Genes:
- Pollution dependency: +3 metabolism. Carriers will find it hard to breathe outside of polluted areas (50% max at worst)

- Severe pollution dependency: +6 metabolism. Carriers will be severely impaired outside of polluted areas (25% max at worst, will also fall unconscious)

- Lethal pollution dependency: +9 metabolism. Carriers will quickly die outside of polluted areas (0% max at worst, will die)

Also includes a gene to nullify the various pollution dependencies

Remember to quickly expose the new carriers to pollution after implanting them to prevent any health issue