cleaned up controller and added some addshift functionality

SchedulerApp/.idea/runConfigurations.xml

...pp/src/main/java/com/example/schedulerapp/Controller.java

...ain/resources/com/example/schedulerapp/addShiftPopup.fxml

...ces/com/example/schedulerapp/schedBottomPanelManager.fxml

...urces/com/example/schedulerapp/staffManagerSidePanel.fxml

.../target/classes/com/example/schedulerapp/Controller.class

...arget/classes/com/example/schedulerapp/addShiftPopup.fxml

...ses/com/example/schedulerapp/schedBottomPanelManager.fxml

...asses/com/example/schedulerapp/staffManagerSidePanel.fxml