Allow crossreferencing of labels between fields and presets

[Dimitar5555]

Simply having {preset/....} or {field/....} should allow to use the respective label. If there the keywords (preset/field) aren't present, the script should default to the translations of the current item.

Such change would require changes in two places and could be taken out in a separate function.

https://github.com/ideditor/schema-builder/blob/main/lib/build.js#L529-L531

https://github.com/ideditor/schema-builder/blob/main/lib/build.js#L566-L568

function fetchLabel(label, type, tstrings) {
	label = label.slice(1, -1);
	let separated = label.split('/');
	let labelType = separated.shift();
	let searchIn = tstrings[type];
	let labelAccessName  = type=='preset'?'name':'label';
	if(['preset', 'field'].indexOf(labelType) != -1) {
		searchIn = tstring[labelType];
		labelAccessName  = labelType=='preset'?'name':'label';
	}
	return searchIn[label][labelAccessName];
}

P.S. It might be a good idea for presets to have label instead of name, at least for consistency.