Settings to control whether songs and/or dungeon rewards are shuffled across worlds

[fenhl]

Currently, whether songs/rewards are always in their own world or in any world is determined by their shuffle setting. This means that you need a plando to, for example, have songs be on song locations but in any world, or have dungeon rewards be anywhere in their own world. It has been suggested to add settings to control this explicitly. The setting definitions could look like this, placed directly below the respective shuffle settings:

    cross_world_songs = Checkbutton(
        gui_text       = 'Shuffle Songs Across Worlds',
        gui_tooltip    = '''\
            Allow songs to appear in any player's world.

            If this is off, each player's songs will only
            appear in their own world.

            Regardless of the value of this setting, the
            locations within each world where songs may
            appear is controlled by the "Shuffle Songs"
            setting.
        ''',
        gui_params     = {
            'randomize_key': 'randomize_settings',
            'hide_when_disabled': True,
        },
        shared         = True,
    )

    cross_world_rewards = Checkbutton(
        gui_text       = 'Shuffle Dungeon Rewards Across Worlds',
        gui_tooltip    = '''\
            Allow dungeon rewards (Medallions and Spiritual
            Stones) to appear in any player's world.

            If this is off, each player's dungeon rewards
            will only appear in their own world.

            Regardless of the value of this setting, the
            locations within each world where dungeon
            rewards may appear is controlled by the
            "Shuffle Dungeon Rewards" setting.
        ''',
        gui_params     = {
            'randomize_key': 'randomize_settings',
            'hide_when_disabled': True,
        },
        shared         = True,
    )

This addition would be nice to have for future seasons of the multiworld tournament as well, as we're considering adding this in some form, either as a default or as draft options. To avoid adding GUI bloat, these settings would be hidden when the world_count setting is set to 1.