ADD download functionality

src/main/java/com/ddf/vodsystem/exceptions/JobNotFinished.java

@@ -0,0 +1,7 @@
+package com.ddf.vodsystem.exceptions;
+
+public class JobNotFinished extends RuntimeException {
+    public JobNotFinished(String message) {
+        super(message);
+    }
+}

src/main/java/com/ddf/vodsystem/exceptions/JobNotFound.java

@@ -0,0 +1,7 @@
+package com.ddf.vodsystem.exceptions;
+
+public class JobNotFound extends RuntimeException {
+    public JobNotFound(String message) {
+        super(message);
+    }
+}