Fills the arena mode spawn table

arena-list.lua

--add races to the arena spawn list
local arena_spawn=df.global.world.arena_spawn
arena_spawn.race:resize(0)
arena_spawn.caste:resize(0)
for num,race in pairs(df.global.world.raws.creatures.all) do
    for caste_id,caste in pairs(race.caste) do
        arena_spawn.race:insert("#",num)
        arena_spawn.caste:insert("#",caste_id)
    end
end
arena_spawn.creature_cnt:resize(#arena_spawn.race)
--todo populate items
--arena_spawn.item_types[0]:insert("#",{new=true,item_type=0})