make helper functions in rented instance data class

app/src/main/java/eu/m724/vastapp/vastai/data/RentedInstance.kt

@@ -72,4 +72,26 @@ data class RentedInstance(
             )
         }
     }
+
+    /**
+     * returns whether the instance is running
+     * this is true also if the instance is stopping
+     * vice versa, false if stopped or starting
+     * @return is the instance running
+     */
+    fun isRunning(): Boolean {
+        return status == "running"
+    }
+
+    fun isStopping(): Boolean {
+        return status == "running" && targetStatus == "stopped"
+    }
+
+    fun isStarting(): Boolean {
+        return status == "exited" && targetStatus == "running"
+    }
+
+    fun isChangingState(): Boolean {
+        return isStopping() || isStarting()
+    }
 }