Bug 29001: Fix framework edition when subfields are reordered

Bug 29001: Fix framework edition when subfields are reordered

There is a flaw when subfields are ordered, the inputs are not retrieved
correctly.
We should not rely on the order but use an id instead.
Test plan:
Create, edit subfields
Modify values from the different subfields
Confirm that values are correctly saved

Signed-off-by: Thibault Kero <thibault.keromnes@univ-paris8.fr>
Signed-off-by: Joonas Kylmälä <joonas.kylmala@iki.fi>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>