Fix some weird issues (if, plantgrowth, ..)

- plant_growth tag didn't handle potatoes/etc. that don't have an enum
name, even though the property did
- entity explodes would entirely not add a block list instead of letting
it be left empty
- if command would double-pass arguments. EG: - if true narrate
<&lt>player.name<&gt>
In that example, it would narrate the player's name... it now literally
narrates <player.name> as expected.