on_new callback on save_load widget is not well documented

[mrdobalina2k]

I could see from the typescript, that on_new is called whenever you chose "save as". I would expect the save_as callback to be called "save_as", and that there would be a "New item" ui element that would call the "on_new" callback in that case.

 <SaveAsDialog
        isOpen={isSaveAsDialogOpen}
        onClose={() => setIsSaveAsDialogOpen(false)}
        onSubmit={(name) => {
          if (showSaveConfirmation) {
            showSaveConfirmation(
              `Are you sure you want to save as "${name}"? This will create a new item with your current data.`, 
              () => {
                handleNew(name);
                onClose();
              },
              "Confirm Save As"
            );
          } else {
            handleNew(name);
            onClose();
          }
        }}
        defaultName={selectedId ? 
          (items.find(item => item.id === selectedId)?.label || "") + " (Copy)" : 
          "New Item"}
      />