Switch Impl types to Holderable

[Machine-Maker]

Includes a demo of API to create arbitrary TrimPattern instances.

TrimPattern newPattern =  TrimPattern.create(builder -> { // builder is the registry entry builder 
	builder.assetId(Key.key("whatever:whatever"))
		.description(Component.text("COOL"))
		.templateItem(ItemTypeKeys.RED_WOOL)
		.decal(false)
});

ArmorTrim trim = new ArmorTrim(TrimMaterial.QUARTZ, newPattern);
// newPattern can now be used anywhere TrimPattern could before

[Machine-Maker]

I moved the API-related changes to another PR so this is just server impl changes. Those are more immediately important.

[Machine-Maker]

I added Instrument/MusicInstrument to this too, but I did not add support in ItemMeta for it, ItemMeta won't support direct holders due to serialization issues. But with this, data components should support at least getting them. Creating new ones is a separate issue for another PR.