used get CategoryBudget endpoint in client, date buttons now refreshes tabs

src/de/deadlocker8/budgetmaster/logic/ServerConnection.java

src/de/deadlocker8/budgetmaster/ui/ChartController.java

src/de/deadlocker8/budgetmaster/ui/Controller.java

src/de/deadlocker8/budgetmaster/ui/HomeController.java

src/de/deadlocker8/budgetmaster/ui/PaymentController.java

src/de/deadlocker8/budgetmaster/ui/Refreshable.java

...deadlocker8/budgetmaster/ui/cells/CategoryBudgetCell.java

src/de/deadlocker8/budgetmaster/ui/cells/PaymentCell.java