Implement the ability to export and import scores that one may play

[hvalfangst]

Syntax:
{NOTE},{OCTAVE},{WAVEFORM},{DURATION};

Example (C,D,E in octave 4 as Sine):
C,4,Sine,0.5;D,4,Sine,0.5;E,4,Sine,0.5;

[hvalfangst]

The original idea of using JSON as format is bad as it only introduces unnecessary dependencies (serde, serde-json, serde-derive). Let's keep it simple by instead just using plain old text.