Fix S2259 FP: ValidatedNotNullAttribute in extension method

[pavel-mikula-sonarsource]

When ValidatedNotNullAttribute is used in an extension method, the effect is not recognized by the engine:

    <Extension>
    Public Sub CheckNotNullExtension(Of T)(<ValidatedNotNull> Value As T, Name As String)
        If Value Is Nothing Then Throw New ArgumentNullException(Name)
    End Sub

    Public Sub LogExtension(Value As String)
        Value.CheckNotNullExtension("Value")
        If Value Is Nothing Then
            Console.WriteLine(Value.ToString)  ' Noncompliant FP, this code is not reachable
        End If
    End Sub

because there's different method symbol interpretation of the extension methods:
C#: CheckNotNullExtension(Value, "Value")
VB: Value.CheckNotNulLExtension("Value")