Handle duplicate dependencies gracefully

[adamzip]

Context

The dependency update part of the codeflow fails whenever it reads a Version.Details.xml file that has duplicate entries for the same dependency name. This was the intended behavior when the feature was designed.
However, it happens occasionally that a bad git merge leads to duplicate entries for a single dependency, and it can be quite time consuming to fix by hand, because the codeflow algorithm may keep looking at previous commits where the duplication existed, even if we create a new commit to remove duplicates.

Goal

We should implement a solution to handle duplicate dependencies in Version.Details.xml without failing.
Decide between one of the two following approaches:

• When updating a dependency, execute the update on every depenency in the versioning file that matches the dependency's name.
• When updating a dependency, update the first dependency that matches the name, and delete all subsequent duplicates that may exist in the file.