Fix for unit tests empty file string.

Author: HeroponRikiBestest

BinaryObjectScanner/FileType/InstallShieldCAB.cs

@@ -24,7 +24,8 @@ public bool Extract(string file, string outDir, bool includeDebug)
         /// <inheritdoc/>
         public bool Extract(Stream? stream, string file, string outDir, bool includeDebug)
         {
-            file = Path.GetFullPath(file);
+            if (file != "")
+                file = Path.GetFullPath(file);
             // Get the name of the first cabinet file or header
             var directory = Path.GetDirectoryName(file);
             string noExtension = Path.GetFileNameWithoutExtension(file);