Instead of requiring a run with an explicit `--ihave1111and2222`, detect
whether the routable addresses are set up and if not, then skip the test.
To detect whether the addresses are set use `bitcoind` - start it
and ask it to bind on them and see if it will error with
"Unable to bind". Since this is what the tests do anyway, just start
the nodes and see if an exception will be raised like
`FailedToStartError` / "Unable to bind".
This makes it possible for the CI to run
`feature_bind_port_discover.py` and
`feature_bind_port_externalip.py` by just setting up the
addresses, without having to explicitly provide `--ihave1111and2222`.
Co-authored-by: willcl-ark <will@256k1.dev>
In the functional tests there are lots of cases where we assert != which
this new util will replace, we also are adding the imports and the new assertion
If `-bind=` is provided then we would bind only to a particular address
and should not add all the other addresses of the machine to the list of
local addresses.
Fixes https://github.com/bitcoin/bitcoin/issues/20184 (case 4.)
