GroupMetadataChange
A group-definition metadata change between two versions.
from_group/to_group are the group's fully qualified paths in the parent and target trees;
they differ when the group was renamed or re-parented. The remaining fields carry the post-change
value of any attribute that changed and are null when that attribute was unchanged.
Qualified path of the group in the parent version's tree.
Stable UUID of the group.
New hidden flag, when it changed.
New missing-column policy, when it changed.
New tags, when they changed.
null
New title, when the title changed.
Qualified path of the group in the target version's tree.
