Replace get blood type with set blood type

[MrMelbert]

Setters are better than getters.

The only reason they were getters initially is because I was lazy and didn't want to account for all the places blood type could change. Turns out that's not too many cases.

I took the opportunity to buff up our blood type / dna handling

• Pre-made viruses no longer have no blood types
• Unknown dna blood now has slightly more descriptive names
• Organs more accurately update their tracked/internal blood type
• Bugs and stuff have unique blood types (same as animal though, for now)
• Pandora / Heirophant no longer have blood
• A few robotic things now have oil blood as expected
• Ice demons have bluespace blood
• Plant mobs have water blood