Small updates: Less folder creation messages + clarified description

[Kewlan]

• When creating custom music folders, skip if top dir exists. Will speed up app start, but if folder structure is changed it'll have to be manually removed. Add a safety check to create the node's folder if it doesn't exist during seed gen.
• Clarify in the Guarantee New description for Random GS Locations that the original location will be used if no new exist or could be chosen.
• Temporarily remove new GS loc in Zelda's Garden, as it can become inaccessible depending on story flags.