RichText and ScrollView enhancements

[rh101]

Describe your changes

Add support for the "id" attribute to RichText XML anchor, paragraph, header and custom tags. The ID is saved as the name of the node (via setName()).

Add support for adjusting font/size/color of paragraph elements in RichText.

Move scroll to item support from ListView to the base class ScrollView, since it applies to ScrollView nodes as well.

Add support for finding a protected node in a ScrollView via the name.

All of the above changes can be combined together when a RichText is child of a ScrollView, allowing the user to click on a link that takes them directly to another section of the RichText (scrolling the ScrollView to that point).

For example, taking this input:

<h1>Quick Links</h1>
<a href="#fancy_header">Jump To Fancy Header</a><br/>
<a href="#paragraph_2">Jump To Second Paragraph</a><br/>
<a href="#some_link">Jump To Web Search</a><br/>
<br/>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Purus faucibus ornare suspendisse sed nisi. Viverra aliquet eget sit amet tellus cras adipiscing. Ut tellus elementum sagittis vitae. Risus feugiat in ante metus dictum at. Semper eget duis at tellus at. Iaculis eu non diam phasellus vestibulum lorem sed risus. Sed vulputate odio ut enim. Morbi tristique senectus et netus et malesuada fames.</p>
<h1 id="fancy_header">Fancy Header</h1>
<p id="paragraph_2">Cras sed felis eget velit aliquet sagittis id consectetur purus. Turpis nunc eget lorem dolor sed viverra ipsum nunc. Ultrices tincidunt arcu non sodales neque sodales ut etiam sit. Risus feugiat in ante metus dictum at tempor. Id neque aliquam vestibulum morbi blandit cursus risus.</p>
<a id="some_link" href="https://google.com">Google!</a>

auto* richText = ax::ui::RichText::createWithXML(text);
scrollView->addChild(richText);
// ... some code to update the inner container size of the ScrollView to match the RichText size
// now add the hyperlink click handler
richText->setOpenUrlHandler([richText, scrollView](std::string_view url) {
        // Check if the href starts with a "#" character
	if (url.starts_with('#'))
	{
		auto* node = richText->getProtectedChildByName(url.substr(1));
		if (node)
		{
                        // Scroll to the location of that node, and the reason it works is because
                        // the ScrollView inner container is the same height as the RichText
			scrollView->scrollToItem(node, Vec2::ANCHOR_MIDDLE_TOP, Vec2::ANCHOR_MIDDLE_TOP);
		}
	}
	else if (!url.empty())
	{
		Application::getInstance()->openURL(url);
	}
});

A test case showcasing this functionality has been added to the cpp-tests project (RichText test 22).

This functionality should not impact any existing usage of ScrollView, ListView or RichText.

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