Add default recipes for `Folder Format` and `Item Format`

[hced]

If messing up the Folder Format and Item Format fields, afaik there's no going back to default values other than resetting the whole Chord Song prefs? Similar to how you can revert back to defaults for Sort, it would be nice to have the same for Folder Format and Item Format.

(Also, speaking of "Folder" format, if this refers to what's called "Groups" elsewhere, I suggest using the same term here as well: "Group Format".)

[hced]

Edit: There is a Default menu item, but that resets both Folder and Item formats. The Sort menu shows the actual recipes which is nice.