Fix 'errors' and 'collapse' styles for admin and integration config forms.
If admin form fields contain an error, the template adds an 'error' CSS class

to the field div. The correct style is actually 'errors', which has styles

specified in admin.less, and prevents hiding in collapse.js.
The Integration config form template also needs to include collapse.js so that

the 'collapse' style actually has the Show/Hide behavior.

Used 'collapse' as a style for an integration config form.

Saw correctly working behavior with and without errors.