vgmdb_importer: split multiple catalog numbers

[y-young]

While VGMdb uses '~' to annotate multiple catalog numbers, it's encourged to split it in MB.

Tested with:

• https://vgmdb.net/album/69031 (ZTTL-0087~96)
• https://vgmdb.net/album/17317 (VTCL-60187~8)
• https://vgmdb.net/album/8075 (MMCC-4088)
• https://vgmdb.net/album/77315 (N/A)