[FEATURE] The addAnchor setting is now valued

Checking the checkbox "Add link anchor" in a fluidcontent_core provided content element had no effect.

This change results in an `a` tag being rendered at the top of the content element.
Please add line breaks and/or use `fcc:tag` inline with the `f:if` you used here as last segment. But don't forget to break lines around the 130 char mark.