[Vector] Remove default styling properties for polygons that aren't supported for vector

[makella]

After talking with @donflopez and understanding the constraints of all default properties for polygon features blocking vector rendering, we decided, let's go ahead and remove them.

These properties are specifically for smoother rendering between polygons and lines and are more important for things like choropleth maps.

But with vector rendering, we are noticing better lines on the published map than with raster:

In addition, anytime you change styling in the forms the polygon-gamma and line-comp-op properties are reset and no longer persist through to the users styling.

We can go ahead and remove the properties that are blocking and default to the CartoCSS below for polygon fills:

#layer {
  polygon-fill: #374C70;
  polygon-opacity: 0.9;
  line-color: #FFF;
  line-width: 1;
  line-opacity: 0.5;
}

Which with vector will look like this:

cc @saleiva

[makella]

And as mentioned in this issue (#1624) we should remove it from Auto-Style as well.

I can do the PR if you need, just let me know!

thanks

[rochoa]

This is already done.