Remove wrapping div with inline styles for hidden form fields.

We are dropping HTML 4.01 and XHTML strict compliance since input
tags directly inside a form are valid HTML5, and the absense of
inline styles help in validating for Content Security Policy.
Merge pull request #14738 from tilsammans/pull/11407

Remove wrapping div with inline styles for hidden form fields.

Conflicts:
	actionview/CHANGELOG.md