[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.
If you're using PHPStorm it tries to be "smart" about indentations and will add tabs mixed with spaces. We prefer to just indent the next line by one tab, making the continued line start at the same indentation level as child tags. So where you currently have "tab-tab-tab-space" it should be just "tab-tab".