Add error class to the fields wrapper after job submission

If some fields are invalid during form submission, the form shows a red error message at the very top, referencing the fields that are invalid, but doesn't add error class to fieldset wrapper due to which theme developers cannot style the invalid fields.

For example, if user provides an invalid email the following error will appear at the top of submission form:


But the actual field will have no indicator (e.g. red border) since there is no error class applied to the fieldset container.


It would be great, if you can add an error class to fieldset wrapper in this case, which will allow theme developers to uniquely style the troubling fields.

Start by tracing how the submission form renders its fieldset wrappers and handles invalid fields after job submission. Reproduce the issue with an invalid email; done means the affected fieldset receives an error class that theme developers can target.

Written by the indexing model from the issue text.