passes board style and colour and Piece style enums to the template in ProfilePage
changes Square.styles property names to descriptive labels (instead of uppercase codes)
capitalises Piece.sizes labels and uses hardcoded value for DEFAULT_SIZE
removes text-align: right from input pair labels on ProfilePage
adds boardSize and boardStyle to User prefs
ProfilePage prefs - adds preview board and refactors template to get options from the enums in Board etc