Richard's Rage Dog Carry and Throw System

[unreference]

This closes #6475.

I thought this was pretty funny. This allows Link to carry and throw dogs like Ruto.

• Dogs offer carry when Link is nearby
• Thrown dogs deal Megaton Hammer damage with impact effects
• Dogs will bark on landing and then return to Link, as if playing fetch
• Carrying persists across scene transitions while Dogs Follow You Everywhere is enabled

I added a couple helper functions to z_player.c because I felt it was easier and more readable than inlining everything. The underlying functionality is identical -- it's just organized better since this feature interacts with the same functions. Ruto's mechanics are otherwise identical to the original game.