Duplicated records (981): optimize display and export

[jenniferward]

Two requests for the new 981 field:

The list of duplicated records can get quite long, for example https://muscat.rism.info/admin/sources/1001284610 where the "Duplicated from"s take up nearly half the record screen length. Can this be optimized? Display the first, then the last?

DUPLICATED FROM	1001284278, 2024-02-18 19:28:36
...
DUPLICATED FROM	1001284494, 2024-02-20 12:41:52

Also, the field needs to be removed from the MARCXML export.