Refactor: libcrmcluster: pcmk__node_status_t:id -> cluster_layer_id

Also update a lot of log messages to use %PRIu32 instead of %u. But
don't worry too much about specifying "cluster layer ID" within the log
messages right now, nor about changing other variable names.

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>