Merge monograph parts should transfer holds to resulting part

[Michele Morgan]

Evergreen 2.9.1

This report is related to https://bugs.launchpad.net/evergreen/+bug/1406786

When merging monograph parts, multiple part entries can be selected and merged to the chosen prevailing part. All copies are then properly mapped to the chosen prevailing part and the non-prevailing part(s) are flagged as deleted.

If there are part level holds on any of the non-prevailing parts, they are not moved to the prevailing part. Instead, they remain on the parts that are now flagged as deleted. These holds will never be filled since all the copies have been remapped to the prevailing part.

When parts are merged, any part level holds on non-prevailing parts should also be moved to the chosen prevailing part.

To reproduce/test:

Add parts to a bib record, for example, "v.1" and "Vol. 1"
Add a copy and assign the part "v.1"
Add a copy and assign the part "Vol. 1"
Place a part level hold on "v. 1"
Merge the parts "v.1" and "Vol. 1", choosing "Vol. 1" as the prevailing part

Note that part "v.1" now has its deleted flag set to TRUE, but its id remains the target of the hold.

[Lynn Floyd (lfloyd)]

We are still seeing this in 3.2.