Navi bell item for instant Navi on C up

[djevangelia]

An item for instant Navi that is selectable from the pause menu. Shares slot with Nayru. Press L on slot to toggle item. Only available if setting enable_navi_bell is enabled. Not usable if the area lacks Navi text. Bypasses normal UseItem handling and as such doesn't change held item or item action etc.
Uses an unused byte in the vanilla save context to save flags that the player has Nayru and/or Navi to enable toggling.
It uses the Sold Out texture as a placeholder and whoever is interested is welcome to change it freely.
Many icon/texture functions hooked and can be used for other custom item texture loading.
I had thought about making this kind of item for a while and interest in shortening Navi interval was expressed in Discord.

Testing

Tested in ares recently nightly release and Project64 3.0.1.
Looks like this: https://www.youtube.com/watch?v=NI7h6IwZ5Gc (jumping is debug levitate)

Known issues:
Pressing L with no item in Nayru slot shows some temporary glitchiness on the name label.
The child item Sold Out is not greyed out when adult because greying the texture is done on a per-texture basis and not item slot/item basis.
A file that starts with both Nayru and Navi will have Navi in the Nayru slot at first, which could be both good (reminder it's there) and bad (not vanilla).

[flagrama]

Press L on slot to toggle item.

As a non-Navi user this is my only opinion: The control should be the D-Pad Left/Right to be consistent with how you change which trade item you can equip when trade shuffle is on.

[djevangelia]

Yeah, that can absolutely be adjusted in the future when it's clear it is working properly and useful to players 👍
Didn't want to make something too fancy when needed to focus on the icon texture hooks.

[flagrama]

Also adding since I looked at the code for reasons: this should be consolidated with trade quest item swapping, not just use the same controls. lots of duplicate functionality between the two.