Bug 21049: Fix value of material select for Rancor 007 widget

Bug 21049: Fix value of material select for Rancor 007 widget

The material type is selected in accordance with position 0 of 007

Test plan:
1. Create a new record using the advanced editor
2. Select a material type for field 007 and set at least the position 0
   of this field
3. Save the record and reload the page
4. The material type should remain selected
5. Try with all available material types

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit e85294a738da7cce2a4897998ffa795f977b4cd7)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit d5aa7655a643a5a4868a47b8aae5371438993580)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
(cherry picked from commit b25c4196b8174b375d8c13ccb8dee145c5d784b6)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>