#235 - added modals for download and starting

...dlocker8/budgetmasterclient/ui/controller/Controller.java

...erclient/ui/controller/LocalServerSettingsController.java

...er8/budgetmasterclient/ui/controller/ModalController.java

...rclient/ui/controller/OnlineServerSettingsController.java

...de/deadlocker8/budgetmasterclient/utils/LoadingModal.java

...rces/de/deadlocker8/budgetmaster/languages/_de.properties

...rces/de/deadlocker8/budgetmaster/languages/_en.properties

...dlocker8/budgetmaster/ui/fxml/SettingsTabLocalServer.fxml

...java/de/deadlocker8/budgetmaster/logic/utils/Strings.java