Add properties Section and SubSection for class ConfigurationEntry

The simple git config file syntax:

[section "subsection"]
	keyname = value

Add properties Section and SubSection for class ConfigurationEntry

public class ConfigurationEntry<T>
{
	protected ConfigurationEntry();
	protected internal ConfigurationEntry(string key, T value, ConfigurationLevel level);

	public virtual string Key { get; }
	public virtual string KeyName { get; }		
        public virtual string Section { get; }
        public virtual string SubSection { get; }
	public virtual T Value { get; }
	public virtual ConfigurationLevel Level { get; }
}

Version of LibGit2Sharp

0.26.0.0

Locate the ConfigurationEntry class and the code that parses Git configuration entries. Check how section and subsection values are represented, then expose Section and SubSection as specified in the issue. Done means callers can read both properties for entries using the shown Git config syntax, with existing configuration behavior preserved.