tdf#92571: add mime types for several image file formats

The new mime types were added the followings:
   - eps -> image/x-eps
   - wmf -> image/x-wmf
   - bmp -> image/bmp
   - pct -> image/x-pct
These new mime types are written in the attribute "media-type"
of each image in the file "manifest.xml"

Change-Id: I16edb625e331d3f917c6e8929df004191e317acc
Reviewed-on: https://gerrit.libreoffice.org/17123Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
Tested-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

svx/source/xml/xmlgrhlp.cxx

@@ -471,7 +471,11 @@ OUString SvXMLGraphicHelper::ImplGetGraphicMimeType( const OUString& rFileName )
         { "png", "image/png" },
         { "jpg", "image/jpeg" },
         { "tif", "image/tiff" },
-        { "svg", "image/svg+xml" }
+        { "svg", "image/svg+xml" },
+        { "wmf", "image/x-wmf" },
+        { "eps", "image/eps" },
+        { "bmp", "image/bmp" },
+        { "pct", "image/x-pict" }
     };
 
     OUString aMimeType;