Dev into master

See merge request !2

Resolve "Jede Menge offene Tabs - mit Rechtsklick schließen"

See merge request !1

feat: qui select has now a new option to save the current value state in locale storage -> option: localeStorage

feat: qui/controls/desktop/Panel -> new method implemented: showSavedIconAnimation + showErrorIconAnimation

feat: refactor: ajax request can now respond to server errors :: onError will be triggered at ajax failures

feat: qui/controls/loader/Loader -> opacity can be passed as attribute and style can be manipulated before opening