[FEATURE] Re-use form features for Output edit action

This patch removes the partials for the form fields generated by
the OutputController and replaces the with the default form fields.

Additionally a loop over the form pages was introduced to display the
fieldset headers and to prevent an error when an invalid array access
is used for the pages object storage.

For this change to work the PrefillViewHelper now accepts an answer
as an additional argument and the answer argument is passed on to this
view helper in the form field partials that are used in the
OutputController.

Some commented code is removed from the Input partial because the
ViewHelpers will still be executed otherwise.

Resolves: #56201
Releases: 2.1
Change-Id: Iba9e84adc3f983d76ef8f2d5939654cb7faec1ed