Update savefile format for 3.0.0

[papjul]

Here is what I did:

• I ran savefile/parse_smmh.py which gave me a few missing keys errors.
• I manually completed savefile/save_keys.json with null values for the new keys. I also fixed 419281215 is the villager folder number #16 at the same time.
• I re-ran savefile/parse_smmh.py

I tested the save_schema_655400_655362.json file and I was able to read a save file with it.