Spearwork

Made changes to spear+shield combo. 

• When a shield is in the main-hand and a spear in the off-hand, the player can use left-click to charge the spear. This can be paired with a shield to block incoming damage.
• Made the trident have spear mechanics, but maintained its throw. Can be used in sync with the shield just like the spear.

Known issues:

- Vanilla Minecraft has instances where the entity is attacked by a spear charge, full animation, knockback, and sound, but the damage does not go through. Because of that, it occurs in this mod as well, but without the visual or sound cues. Using this mod, the player may find that charging with a spear may cause an entity to be knocked back without taking damage. Just know that this is a vanilla issue, not a mod issue. The only mod issues are the visual and sound cues not happening.