[BUGFIX] Additional Identity Properties not set on mapping error

When binding Fluid forms to nested objects, Fluid automatically adds
hidden fields with the identifiers of all affected objects so that
the persistence layer can update all objects correctly.

When a form was redisplayed due to property mapping errors, the
identity fields for the nested sub objects were no longer created.

This change fixes this by making sure all identity fields are rendered
recursively also after property mapping errors.

Backport from #29290
Resolves: #59253
Releases: master
Change-Id: Ib4b2a065d967e87aa42bdc889fef3f0b727b748b
Reviewed-on: http://review.typo3.org/30502
Reviewed-by: Stefan Froemken <froemken@gmail.com>
Tested-by: Stefan Froemken <froemken@gmail.com>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>