C#: Improve cs/web/debug-binary to repect the RemoveAttributes transformation.

[michaelnebel]

The issue that is referring this PR provides some more information.
Basically, we should disregard debug=true in case there exist a transformation that removes the debug attribute (a transformation file in the same folder as the Web.Config file).
E.g. if there exist a transformation file with content like

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
  <system.web>
    <compilation xdt:Transform="RemoveAttributes(debug)" />
  </system.web>
</configuration>

then we can disregard debug=true in the Web.config file.
According to Microsoft documentation the tag doesn't need to be under system.web.

[michaelnebel]

The DCA results show that we need to narrow the application of the transformation files to not miss any true positives.
Narrowing the implementation such that we assume that a transformation only applies in case it is the same folder as the config file.

[michaelnebel]

The DCA execution looks fine.
(1) The alerts that have disappeared are all because there is a Web.Release.config next to the Web.config that removes the debug attribute.
(2) DCA reports that cs/web/debug-binary query is a bit slower on the mono project. Running the query locally doesn't exhibit the same slowdown factor. The query is expected to be slightly slower, which is also the case.

[hvitved]

LGTM