Long file paths prevents cloning all nested submodules (CA-316)

[amoeder]

On my windows pc, I cannot recursively clone all nested submodules contained in this repo except from in the C: root.

Within the subfolders, there are a number of redundant and overly-descriptive directory names that could be shortened or eliminated.

There are also nested submodules that are duplicates of submodules that already exist higher up the tree (maybe different versions, though which is also confusing).

I realize that some of these issues stem from submodules themselves, but it seems like this ought to be reorganized and cleaned up.