`ToCss` returns unescaped property names

[MartinWelsch]

Bug Report

Prerequisites

• Can you reproduce the problem in a MWE?
• Are you running the latest version of AngleSharp?
• Did you check the FAQs to see if that helps you?
• Are you reporting to the correct repository? (there are multiple AngleSharp libraries, e.g., AngleSharp.Css for CSS support)
• Did you perform a search in the issues?

For more information, see the CONTRIBUTING guide.

Description

Consider the followig program:

using System;
using AngleSharp;
using AngleSharp.Css.Parser;
					
public class Program
{
	public static void Main()
	{
		const string stylesheetText = @".className { --\/prop: value; }";
        var parser = new CssParser();
        var style = parser.ParseStyleSheet(stylesheetText);
		
		Console.WriteLine(style.ToCss());
		// prints:
		// .className { --/prop: value }
	}
}

The property named --/prop is written literally which results in invalid CSS.

Expected behavior: style.ToCss() to return .className { --\/prop: value }

Actual behavior: style.ToCss() returned .className { --/prop: value }

Environment details: .NET6, AngleSharp.Css 0.16.4

Possible Solution

CssProperty should escape Name using CssUtilities.Escape(Name)