Set name of child bioassay when there is only one parent

[Nicklas Nordborg]

Currently, the BioAssaySet.newBioAssay(BioAssay) copies the name of the parent bioassay to the child bioassay. It is possible since there is only one parent. The BioAssaySet.newBioAssay(Collection) doesn't do the same since there can be many parents. I think this method should also copy the name if the collection only contains a single parent.

The background for this is that the Base1PluginExecuter has two cases that uses the latter method. Case 1 is when there has been a merge of bioassays and there are actually multiple parents. But in this case the new names are included in the import file. Case 2 is when there has been a change in reporter-position mapping. In this case there is still only one parent for each child and there is no new names in the import file. The result is that all children are named "New bioassay" making it harder to trace them back to their parents.

[Nicklas Nordborg]

(In [4623]) Fixes #1163: Set name of child bioassay when there is only one parent