As part of RPCs processing, they need to be sorted reliably across all
peers, so that unique IDs can be assigned to greatly optimize the
network layer.
The RPC configuration nodes are stored in dictionaries which, until
recently, always casted StringName keys to String.
Since method names (keys) in the RPC configuration were StringName,
a side effect of the above change is that sorting the dictionary keys no
longer sort them alphabetically by default (StringName are compared
using their pointers).
This commit changes the RPC processing logic to use sort_custom to
provide a function that can handle the StringName comparison.
32e4ab91e8