AudioStreamSample: Don't crash when writing to file fails
Created by: merumelu
AudioStreamSample::save_to_wav
would crash Godot if you tried to save to a path that didn't exist or where it had no write access. I also changed it to return Error
so the developer can react in such cases, this shouldn't be a BC break as the method didn't return anything previously but maybe this PR can also still slip into 3.1 :)
Docs for the method were added as well.