Added beginner-friendly methods for ItemType

[Zbizu]

Pull Request Prelude

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

Changes Proposed

Make equipment checks more pleasant to code

New methods:

itemType:isHelmet()
itemType:isArmor()
itemType:isLegs()
itemType:isBoots()
itemType:isWeapon()
itemType:isBow()
itemType:isWand()
itemType:isShield()
itemType:isBackpack()
itemType:isNecklace()
itemType:isRing()
itemType:isAmmo()
itemType:isTrinket()

it just feels more natural to write checks in scripts using these methods