sim shim should use generic dispatch, like the real-robot shim

[jwgcurrie]

py3-naoqi-bridge/shim_server.py uses arbitrary NAOqi calls via getattr(ALProxy(module), method)(*args). Anything callable on a real robot works.

src/shim_server.py (sim) is hand-mapped. Methods it doesn't cover silently return null with HTTP 200, so callers can't tell sim no-ops from real-robot successes.

This issue will track matching the real-robot shim's pattern for the simulation shim. Replace the if/elif chain with a generic dispatcher, plus a small override table for the few cases that don't map cleanly.