Surge++ FX Section

[baconpaul]

FX in Surge++ are complicated and difficult.

Step 1 is to move them over as is without parameterizing the layout so we can at least kill the legacy side. Once that's done we can figure out the right thing to do. But save that.

[baconpaul]

Step 2 is, as I knew, and as I discussed with @mkruselj on slack, to have a separate <layout> block for each FX type which is swappable based on an FX selector. Maybe default those in and just have overrides. And then have the UI engine swap out the sub-layouts appropriately.

So engineering to the XML spec, the parser, the whole nine yards.

Probably add a new type a <hidablelayout> which is a layout subclass when I do this. That would also be useful elsewhere - like the big FM matrix we will need one day.

[baconpaul]

Re-tooling the S++ plan so closing these issues.