Added popup window when 3,1 and 0 hours left

src/main/java/com/application/DB/DB.java

...main/java/com/application/GUI/LineChartFunctionality.java

src/main/java/com/application/GUI/NotificationPopUp.java

target/classes/com/application/DB/DB.class

.../classes/com/application/GUI/LineChartFunctionality.class

target/classes/com/application/GUI/NotificationPopUp.class