TPH's Adaptive Crosshair

HEAVILY INSPIRED BY SURV'S ADAPTIVE CROSSHAIR (https://content.luanti.org/packages/SURV/adaptive_crosshair/) and intends to do the same things. Basically wanted to do my own rendition of it and see how well I'd do lol

Depends on https://content.luanti.org/packages/TPH/tph_wielditem/ for detecting wielded item changes

Shows whether or not held item is:

• edible
• a weapon (sword)
• a ranged weapon (bows, guns if they have the proper groups)
• tool (a part of registered_tools)

Shows whether or not a pointed thing is:

• an entity (even for players or tamed)
• dropped item
• node
• falling node
• liquid (if holding liquids_pointable item)
• formspec (nodes that have formspec functions such as the chest)

If held item has a tool_capabilities with a groupcaps (basically most tools including the hand), and if pointing at a node with groups - it will show a checkmark or cross depending on whether or not your tool is adequate for the job

TODO:

• set up a system for events and callbacks (e.g. callback for a node being pointed at and off, maybe even an on_step)
• show a mouse icon depending on if node or item can be clicked with
• permit custom type (image relating to wield item) and pointable (image relating to what is being pointed at) mechanics
• maybe see about using entity armour groups with tool capabilities???