Update HUD using predicted client data

[Toodles2You]

This change is for multiplayer.

Clients will now have their HUD display/use the values used for weapon prediction, instead of having messages sent to them each time the values update. Clients with prediction disabled won't be affected & will use the existing messages.

The benefit is that the active weapon, clips, and ammo will update without any delays when playing with high ping.

I did a bit of testing & refactoring to make sure it doesn't interfere with singleplayer loading & level changes.

Some notable changes I had to make:

• Weapon prediction is still run when the player has no weapon equipped
• All ammo values are fully sent to the client as part of the weapon data structs
• Client weapons get their ammo types from the 'weapon list' message so they use the correct ammo values

[Toodles2You]

I fixed ammo updates being sent before the HUD was initialized if the gamerules spawn the player with weapons, which would result in the HUD displaying zero ammo.