Decoding obfuscated PSSI data

[troyhacks]

Adds logic to PSSI parsing to deobfuscate the data and make it accessible.

Adds proper parsing to convert previously obfuscated values for mood, end_beat, and bank into integers.

Cleans up the struct for PSSI to pad out the unknowns - opinions may vary on this, I just personally like it tidy.

[dylanljones]

Hi @troyhacks, thank you for adding the code for the PSSI tag!:)

Do you know if Padding from the structs library keeps the byte contents when writing it back to file? I think it just zeros out those bytes, which is not optimal. I also think it is prettier without all of the unknowns, but i want to make sure those bytes stay the same (unless they are always zero anyway).
I didn't spend the time in my collection to add song structure info, so I haven't yet dug into the PSSI tag so much.
But thanks again for your help, will merge as soon as that is clarified.

[troyhacks]

I honestly do not know - I had to give myself a crash course in Python to write this patch.

I would say to leave the unknowns - they aren't hurting anything.

...but I think mood, end_beat, and bank should be translated to integers, as that's what they are.

[dylanljones]

Yes, I totally agree on the known fields and I really appreciate your work:) Could you revert the unknown fields?

[troyhacks]

Reverted them back to bytes!

[dylanljones]

Very nice, thank you!