p2p/simulations/adapters/exec: fix some issues (#21801)

- Remove the ws:// prefix from the status endpoint since
  the ws:// is already included in the stack.WSEndpoint().
- Don't register the services again in the node start.
  Registration is already done in the initialization stage.
- Expose admin namespace via websocket.
  This namespace is necessary for connecting the peers via websocket.
- Offer logging relevant options for exec adapter.
  It's really painful to mix all log output in the single console. So
  this PR offers two additional options for exec adapter in this case
  testers can config the log output(e.g. file output) and log level
  for each p2p node.