Investigate using `rustworkx` instead of `networkx`

I was curious if there was a faster implementation of networkx. Apparently rustworkx is.

ST2 already uses orjson, which is rust-based. So, another rust-based dep like rustworkx seems reasonable.

I wonder how much of a performance boost rustworkx would provide in orquesta? From a quick search, there are a few API differences between networkx and rustworkx that we'd need to account for to play with that.

A few links:

• https://github.com/Qiskit/rustworkx
• rustworkx for NetworkX users (in the rustwokx docs)
• some very limited benchmarks (in the rustworkx docs)
• a sane recommendation for how to deal with rustworkx requiring integer IDs for nodes in the graph (in the rustworkx docs)

Start by locating Orquesta's current NetworkX usage, then compare the relevant APIs with the rustworkx for NetworkX users guide and its benchmarks. Done means providing measured performance results and a clear compatibility recommendation for whether replacing NetworkX is practical.