Bulk Export of submission crash when submission objects with different amount of items in them (repeating groups, uploads)

[LaurensBurger]

Product versie / Product version

2.2.6

Omschrijf het probleem / Describe the bug

Bodegr 39 nopolder: 83 venr: 86 RID: 130

sentry: 340715 Bulk export will crash when 2 submissions have a big difference in keys:

Export generates the headers to merge from submission A:

[
    "Formuliernaam",
    "Inzendingdatum",
    "voornaam",
    "voorvoegsel",
    "achternaam",
    "bsn",
    "straatnaam",
    "huisnummer1",
    "huisletter_persoon",
    "huisnummertoevoegingPersoon",
]

But submission B looks like this:

[
    "Evenementenvergunning aanvragen",
    datetime.datetime(2023, 11, 14, 11, 3, 42, 407842),
    "",
    "",
    "",
    "",
    "",
    "",
    "",
    "",
]

Because

    "voornaam",
    "voorvoegsel",
    "achternaam",
    "bsn",
    "straatnaam",
    "huisnummer1",
    "huisletter_persoon",
    "huisnummertoevoegingPersoon",

are all empty, these components are all part of a step that was skipped for submission B.

This causes the mass export to fail.