Node-name matching for filter-based routing and load-balancer membership.
A node matches a filter when the filter is a substring of (or regex against)
the node name, EXCEPT when the node's short name carries a configured excluded
pattern that the filter itself does not. This keeps a class of nodes — e.g. QA
nodes named <type>_qa@host — out of the general <type> routing set, while a
<type>_qa filter can still reach them.
Exclusions default to [] (no behavior change). Configure them with:
config :rpc_load_balancer, excluded_node_patterns: ["_qa"]