Merge branch 'frontend-testing' into 'master'

...a/no/ntnu/idatt1002/demo/controller/BudgetController.java

...tnu/idatt1002/demo/controller/CreateBudgetController.java

...no/ntnu/idatt1002/demo/controller/ExpensesController.java

.../no/ntnu/idatt1002/demo/controller/FinanceController.java

...a/no/ntnu/idatt1002/demo/controller/IncomeController.java

...nu/idatt1002/demo/controller/IncomeExpenseController.java

...main/java/no/ntnu/idatt1002/demo/controller/MainMenu.java

...no/ntnu/idatt1002/demo/controller/MainMenuController.java

...va/no/ntnu/idatt1002/demo/controller/SceneController.java

...tnu/idatt1002/demo/controller/SelectBudgetController.java

...va/no/ntnu/idatt1002/demo/data/Budget/BudgetRegister.java

...o/ntnu/idatt1002/demo/data/Budget/FileHandlingBudget.java

...idatt1002/demo/data/Budget/FileHandlingBudgetArchive.java

...datt1002/demo/data/Budget/FileHandlingSelectedBudget.java

...ava/no/ntnu/idatt1002/demo/data/Budget/GeneralBudget.java

src/main/java/no/ntnu/idatt1002/demo/data/Budget/MMBI.java

...main/java/no/ntnu/idatt1002/demo/data/Budget/Savings.java

.../java/no/ntnu/idatt1002/demo/data/Budget/SavingsGoal.java

...a/no/ntnu/idatt1002/demo/data/Economics/FileHandling.java

src/main/resources/Economics/Expense.register