Add a option to mark TextArea to be safe

[williamjmorenor]

Hello

I am working in a project that save a HTML template and then must let the user to edit the HTML Markup and then save the edited HTML in the database, I am using the TextArea field to acomplish this task, but I have found that most of the HTML tags are removed in this line:

https://github.com/pallets-eco/wtforms/blob/main/src/wtforms/widgets/core.py#L327

And if a save the form a get a truncated version of the original HTML in the database.

If there a option to mark the textarea_innerhtml as safe? Or this is a feature that can be included in the TextArea field code?