Add metadata for all songs

[x8c8r]

Not much to say. Every song gets these 6 fields filled:

songName
displayName
composers
charters
freeplayColor
freeplayIcon

Data taken from the V-Slice metadata files, apart from the colors, which were sourced from the week files here.

Mostly made to go along with my engine PR since that leaves freeplay in quite a disheveled state since none of the songs have metadata.