Detect symbol references for @keyword identifiers

[pavel-mikula-sonarsource]

Symbol references are not detected in SQ UI for @keyword annotated identifiers in utility analyzer SymbolReferenceAnalyzer

@ref should be annotated. Same as any other @ identifier like @alias or @namespace, etc.

public void Write(object @ref)
{
    Debug.Assert(@ref != null);
    Console.WriteLine(@ref.ToString());
}

Same for VB

    Public Sub Write([Namespace] As Object)
        Debug.Assert([Namespace] IsNot Nothing)
        Console.WriteLine([Namespace].ToString)
    End Sub

Source: Peach
https://peach.sonarsource.com/code?id=lucenenet&selected=lucenenet:Lucene.Net/Util/OfflineSorter.cs&line=548