feat(tests): add a dev test suite

[Rqnsom]

• adds development tests used for some extra side-testing.

  • these are used when synth nodes are run as a separate binary (PR will be delivered later for this functionality)

• every test runs a node forever with a slight variation:

  • dev001_t1_RUN_NODE_FOREVER_with_logs
  • dev001_t2_RUN_NODE_FOREVER_no_logs
  • dev002_t1_MONITOR_NODE_FOREVER_WITH_SYNTH_NODE_sn_is_conn_initiator
  • dev002_t2_MONITOR_NODE_FOREVER_WITH_SYNTH_NODE_sn_is_conn_responder

• also (!): these tests are not yet included in the mod tree! these still do not compile by default - and cannot be compiled yet.

  here's a list of things that will be delivered later to make these tests work:

  • include chrono crate in the Cargo.toml
  • pull out and separate the crawl module from the crawler binary
  • add a new wait_until_exit API to the node