Fix issue with item decay

[MillhioreBT]

Pull Request Prelude

• I have followed [proper The Forgotten Server code styling][code].
• I have read and understood the [contribution guidelines][cont] before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

with these changes you can configure any item for decaying
example:

local talkAction = TalkAction("!test")

function talkAction.onSay(player, words, param, type)
    local armor = Game.createItem(2467, 1, player:getPosition())
    armor:setAttribute(ITEM_ATTRIBUTE_DURATION, 1000)
    armor:setAttribute(ITEM_ATTRIBUTE_DECAYTO, 2173)
    armor:setAttribute(ITEM_ATTRIBUTE_DECAYSTATE, 0) -- or armor:setAttribute(ITEM_ATTRIBUTE_DECAYSTATE, DECAYING_FALSE)
    armor:decay()
    return false
end

talkAction:register()

or

local talkAction = TalkAction("!test")

function talkAction.onSay(player, words, param, type)
    local armor = Game.createItem(2467, 1, player:getPosition())
    armor:setAttribute(ITEM_ATTRIBUTE_DURATION, 1000)
    armor:decay(2173)
    return false
end

talkAction:register()

The problem is that canDecay is checking the time of the itemType only, instead of taking into account the time defined directly to the item

Issues addressed: Nothing!