Is your feature request related to a problem? Please describe.
When using the API, I would like to be able to tell the difference between these two diffs:

<file state="changed">
  <old name="syn-2.0.68.tar.gz" md5="01a9bc27d9bb67760e8736034737cd20" size="265035"/>
  <new name="syn-2.0.87.tar.gz" md5="112875c142d1023400b0262ea1996de0" size="278076"/>
  <diff lines="11568" shown="0"/>
</file>
<file state="changed">
  <old name="u_dep_xcb.patch" md5="bb506230981852423769256358fab7e7" size="656"/>
  <new name="u_dep_xcb.patch" md5="55523490cbfcd7596dbbf38b9287835c" size="552"/>
  <diff lines="19" shown="0"/>
</file>

One of them is an archive and the other is a text file. If I go and proceed to use /source/<project>/<package>?cmd=diff&view=xml&file=syn-2.0.68.tar.gz with a higher tarlimit/filelimit, I will get a list of files inside of that archive, which is a different behavior than what doing the same thing with u_dep_xcb.patch does. I would like to know that before I fetch individual file diffs.

Describe the solution you'd like
I would like archives to be marked differently in the xml diff list