Add an option to make tree merging sensitive to authors

[maxpatiiuk]

When merging tree nodes, all children with the same name and rank are merged together.
However, there are cases when the name might be the same, but the author different, and user expects these nodes not to be merged.

Need to add an option to make tree merging sensitive to node children

Here is where it happens in the code:

specify7/specifyweb/specify/tree_extras.py

Line 189 in aaede22

matched = [target_child for target_child in target_children