Loot table generation improvements

[Leo40Git]

• Added JCondition#parameter(String, JsonElement), along with primitive value overloads
  • These make JCondition a bit less awkward to use (since you no longer have to create a JsonObject beforehand)
  • Also added JCondition#condition(String). It's exactly what you think it is
• Added JFunction#set(JsonObject) and JFunction#parameter(String, JsonElement), along with primitive value overloads
  • Conditions and functions are surprisingly similar (less so when you consider that conditions are specialized functions...)
  • Speaking of, JFunction#function(String) now exists
  • Also renamed JFunction#add(JCondition) to condition to make it more intuitive
• JEntry's children are now proper JEntry instances instead of raw JSON
  • JEntry#child(String) has been deprecated as a result
  • Also added JEntry#function(String) and JEntry#condition(String) for easier adding of simple functions/conditions (like "minecraft:survives_explosion")
• This also fixes the loot table entry's conditions list being output as "condition" rather than "conditions" (#20)

[Devan-Kerman]

lgtm

[Devan-Kerman]

released