[folding] Optionally fold chained method calls

[aaronhoffman]

For frameworks that expose a fluent API (ex: d3.js), it is common to chain method calls on separate lines. Example here:

d3.select(".chart")
  .selectAll("div")
  .data(data)
  .enter()
  .append("div")
  .style("width", function(d) { return d * 10 + "px"; })
  .text(function(d) { return d; });

Currently, the vscode editor.foldAll command folds these chained method calls and hides everything except the first line d3.select(".chart").... It would be nice to optionally enable/disable this functionality based on your use case. (In my case, I would disable it by default for all languages.)

Likely related to folding not being language aware: #3422

[aeschli]

Yes, this would need language awareness.