[FEATURE] Durability for Off-Hand items in Durability Hud Element

[IceTank]

What feature would you like to be added. Add Off-Hand Tool durability option to the "Durability" Hud element.

Is your feature request related to a problem? Please describe. Tools in your Off-Hand do not have there durability displayed by the Durability Hud element.

Additional context Current Hud element. Notice that only one durability value is displayed (the sword) even though two items are held with durability: