Return HTML for a field wrapped in a FIELDSET The main wrapping DIV will contain additional classes if the field is required, disabled or has an error. A class is also output for hte field method name (if the name contains "Sprout\Helpers\Fb::" this is removed) If the field has an explicit ID set, that will be added as a class on the wrapper too. The special attribute "-wrapper-class" can be used to add classes to the wrapper DIV. Multiple classes can be specified, space separated. These classes will be prefixed with "field-element--"