Support for .vstpreset files

[wrenchse]

I think Plugalyzer could be even more useful if we could load vstpresets directly. From what I found it seems pretty straightforward; I'd give it a go myself but haven't worked with JUCE before at all. https://forum.juce.com/t/loading-vstpresets-in-vst3-plugins-do-not-load-correctly/47111/2

PS. I love this tool, super well made!