Error message for invalid files

Author: karthika-g

src/LCT.PackageIdentifier/Scanner.cs

@@ -62,6 +62,13 @@ public static List<string> FileScanner(string rootPath, Config config)
                     }                  
                 }             
             }
+
+            if (allFoundConfigFiles.Count == 0)
+            {
+                Logger.Error("Provided package file path do not contain valid input files.");
+                Environment.Exit(-1);
+            }
+
             Logger.Logger.Log(null, Level.Notice, $"\n----------------------------------------------------", null);
             return allFoundConfigFiles;