NPE on add lore without first setting lore

[ms5984]

NPE upon adding simple lore string

Additionally

Arrays.asList(T...) is not null-safe in terms of handling varargs. What we actually want to have is an empty List that can be added to if needed; this could be done on the fly.

To Reproduce
Use simple constructor MenuElement(ItemStack) then immediately call addLore(String).

Expected behavior
No NPE.

Additional context
Affects ElementBuilder, FillerBuilder.