dipper.utils.rdf2dot module

A fork of rdflib rdf2dot utility, see https://rdflib.readthedocs.io/en/stable/_modules/rdflib/tools/rdf2dot.html#rdf2dot

We apply the formatliteral function to labels, but otherwise the code is the same

This is necessary for variants with HGVS primary labels that contain characters that need to be url encoded (<, >)

Also replaces cgi.escape with html.escape

TO DO make a PR

dipper.utils.rdf2dot.rdf2dot(g, stream, graph_opts=None)

Convert the RDF graph to DOT writes the dot output to the stream