Make the tag IsImmuneToZombification available to villagers

In version 1.16, with the addition of piglins, there has been added a new NBT tag specifically for them called IsImmuneToZombification, which is useful to mapmakers since piglins turn into zombie piglins seconds after entering the overworld.

I suggest making this tag more useful by extending it's use for villagers too, so if killed by zombies, they only die and don't turn into zombie villagers, regardless of the difficulty. Here is the example:

/summon villager ~ ~ ~ {IsImmuneToZombification:true}

And since Mojang announced adding vultures and undead variants of them, this tag could extend to those as well.