[qa] Attach node index to test_node AssertionError and print messages #13022

In the midst of fighting with #12873 it became apparent that there're a number of assertions and print statements which are emitted by test nodes but don't identify the node in question. This change makes debugging a bit easier by adding identifying information to non-logger test_node-related error messages.

utACK da93b39

A few style nits (ymmv):

• _with_node_id feels like an implementation detail to me. A name like _node_msg could be clear without being overly so.
• For raise_assertion - I'd either remove the indirection or apply it to all raises on the object, given they all use the node id treatment.

@Empact thanks for the review. I've incorporated your good feedback.

concept ACK might also be useful to print out the ports that each node{k} is on - afaict those aren't printed anywhere - and very useful as each bitcoind log identifies peer by a different index and the only way that i'm aware of to tie these to the python test framework indexing is by port num

utACK 80a5e59532925a3445f523a8b3bc29e2e11e8848