[#103289166] Adds and prints debug data

[marchelbling]

It's always a bit dangerous to manually set attributes like self.current_file but the current architecture might not allow something cleaner. So reading your code, the only failures we can have are for textures and mu files. Nothing about cfg? how would that be reported? No other possible failures?

[AurL]

The failure can be everywhere. I added the filenames for the 3 types files we actually read: cfg, .mu and textures.

The most important is the stack trace. The filenames are only here to give more details and spot potentially bad files within the assets.

[AurL]

@mrchlblng can you check when you have time please? I added the debug log file

[marchelbling]

Please add a but of "documentation" telling what is the logic on string within the exporter