Alpheus doesn't track implicit dependency on sub-item of an output folder

[dvoits]

Example:

[1] build -o "files/" "download" 
[2] build -o "metadata.txt" -d "files/data.csv"

The method [2] must run after [1] since if depends on a file of the files folder, therefore there must be an implicit (non-user defined) dependency of [2] on [1].

For instance, the source method for "files/data.csv" must have a "structural" dependency on "files", i.e. affect the execution order.

This should also apply to vector operation. Being enabled, this allows implicit reduce/scatter operations, e.g.

[1] build -o "files/" "download" 
[2] build -o "metadata/*.txt" -d "files/*.csv"
[3] build -o "summary.txt" -d "metadata/"

instead of current syntax:

[1] build -o "files/*.csv" "download" 
[2] build -o "metadata/*.txt" -d "files/*.csv"
[3] build -o "summary.txt" -d "metadata/*.txt"