pre-fill the exact reference when merging publications

When using the merge publications functionality, compare the publication designation for all chosen entries and display the part of the destination that is different in the exact ref field. Eg, if the person wants to merge CUSAS 39 entries, the designation will look like CUSAS 39, 001, CUSAS 30, 004; etc so pre-fill the exact ref with "001" and "004".

https://cdli-dev.mpiwg-berlin.mpg.de/admin/publications/merge-select