Improve Weapon Switching and Pickup Animations

Replace the current weapon-switching behavior with dedicated animations that reflect how each weapon is carried. Pistols could be drawn from and returned to visible chest or thigh holsters, while primary weapons could remain attached to a sling when switching to another item. Weapons collected from the environment should also be physically grabbed instead of instantly appearing in the player’s hands. These changes would make weapon handling feel more deliberate, grounded, and immersive.