ENH: action to join ortholog annotations artifacts (FeatureData[NOG])

[Sann5]

• Previous work in the repo focused on parallelizing the eggnog-diamond-search and eggnog-annotation actions (ENH: Expose cpu param in eggnog-annotate action. #135 ENH: enable parsl parallelization of eggnog-diamond-search #126).
• The chosen strategy implies splitting the input into smaller inputs and running many actions simultaneously on the smaller inputs which in turn have smaller outputs.
• These smaller outputs need to be joined after the eggnog-annotate action which outputs FeatureData[NOG] artifacts, in order to carry out a final analysis for example.
• Therefore there is a need for an action that joins these FeatureData[NOG] artifacts.