Form families of class "Centre" and "Centre Subform" don't translate mnpctrid

[PatrickRWright]

Describe the bug
There are form family types "Centre" and "Centre Subform". I just realized that they exists and they include information on the centre in the column mnpctrid. It would be nice if this is translated. They are not meta data tables.

Probably the issue stems from the fact that one line in the centre forms does not associate with a patient. i.e. there is no mnppid.

Expected behavior
Translate the mnpctrid column into a centre column as for the other non-meta tables.

Additional context
As a side note: There also seems to be a form family type "Image" which we have also not explicitly worked with. Maybe a good idea to have a look into at some point.

[PatrickRWright]

Quick followup since I talked to the DM (@nicoleb7) who implemented the database where the issue was discovered.

The point of centre forms is to be able to enter participants who were screened but are not necessarily recruited. These entries will not be added to the casenodes table. Thus, these forms should be completely detached from the rest of the data. Centre subforms should work like regular subforms just for the centre form case.