Install `create_dependencies.py` with fparser

[hiker]

As raises in a PSyclone review: PSyclone uses the create_dependencies.py script (when importing LFRic infrastructure). ATM PSyclone has a copy of this script, but it might be worth considering to add this script as a binary with fparser.

FWIW, I always considered this more of an example than a binary that fparser should provide. IMHO fparser should not pollute a user's PATH with more binaries. If we decide to add this, I wonder if this could become a special option of fparser2? E.g. fparser2 --create-dependencies or so?