Don't create text node for self closing tags when `alwaysCreateTextNode: true`

Currently I can have the parser create a text node on tags without attributes by setting alwaysCreateTextNode: true. However, for self closing tags, I would like the parser to not create a text node. Right now it creates a text node set to an empty string.

I also noticed that if a self closing tags have any attributes, a text node is not created. It only seems like it's created when a self closing tags have no attributes.

// Given these settings:
const parser = new XMLParser({
	ignoreAttributes: false,
	allowBooleanAttributes: true,
	parseTagValue: false,
	alwaysCreateTextNode: true,
});

parser.parse("<workbookPr defaultThemeVersion="153222" />") 
// "workbookPr": {
//   "@_defaultThemeVersion": "153222"
// }

parser.parse("<workbookPr />") 
// "workbookPr": {
//   "#text": ""
// }

I expect that "#text" is always present, no matter if the self closing tag have attributes or not. But my primary expectation is to be able to have no text nodes at all for self closing tags while still allowing the parser to make text nodes for tags without any attributes.

No source file or test is named. Start by reproducing both parser.parse examples with alwaysCreateTextNode enabled, then trace the self-closing-tag handling from the parser.parse entry point. Done should be confirmed by tests covering self-closing tags with and without attributes and the intended text-node behavior.