Add Complexity Score in CDA Playground Page

Currently the only way to track a complexity score in a CDA request is to console.log the response headers in your code. This is not ideal at all and response headers are never actually used on a frontend platform, all you need is the data. It would be easier if you can quickly get a complexity score when you actually build queries in the CDA Playground (CDA Explorer - datocms.com/cda-explorer). In fact, I really don’t think you should launch this complexity thing until you offer an easy way to track complexity within Dato b/c right now complexity is impossible to figure out manually (the formula is byzantine) and the only option is looking at response headers.