Reading of SFZ improved: loop_mode=no_loop, fixes #21

[mahal]

Improved reading of SFZ files:

• loop_mode=no_loop will no longer loop the sample

https://sfzformat.com/opcodes/loop_mode/

[NickCulbertson]

Wouldn't this flip the default isLooping bool for existing users that haven't set its value, like here.

Would it be possible to use something like isLooping: loopMode != "no_loop" || loopMode != "", or change the line where it is declared to be var loopMode = "no_loop"?

[mahal]

@NickCulbertson Thanks for reviewing. I had the feeling that I'm missing something but couldn't quite point it out; now I know. I have added the line where it is declared as this anyway is the default stated in the sfzformat.com documentation.

[NickCulbertson]

This looks good to me!

cc: @aure