Made sure that the username in the main page is always correct

src/main/java/com/cpsc329pm/AddServiceSceneController.java

...main/java/com/cpsc329pm/DeleteServiceSceneController.java

src/main/java/com/cpsc329pm/EditInfoSceneController.java

src/main/java/com/cpsc329pm/LoginSceneController.java

src/main/java/com/cpsc329pm/MainPageController.java

src/main/java/com/cpsc329pm/StoredServicesController.java

src/main/java/com/cpsc329pm/UserSession.java

src/main/resources/com/cpsc329pm/ReformattedMainPage.fxml