Tag guess: fallback on guessing if tag is empty

[naku]

After importing music, return tags parsed from the zip file If tags are empty, fallback on pattern matching : ex : 00 - Title.mp3 00 Title.mp3 00 Album - Title.mp3

🐋 🐋 🐋 🐋 🐋🐋🐋🐋🐋🐋 Do 2 passes. 1st pass: Find 1st pattern that match all files, apply to all

2nd pass: Find 1st pattern that match any file, apply to all

🐳 🐳 🐳 🐳 🐳 🐳 🐳 🐳 🐳 🐳