* waku_example.c: adapt signature to new parameter 'void* userData'
* libwaku: add new DEBUG request handler to retrieve the list of listened multiaddresses
* waku_example.c: use example the new 'waku_listen_addresses'
* add debug_node_request.nim file
* Thread-safe comms between main thread & Waku Thread - ChannelSPSCSingle.
* Renaming procs from 'new' to 'createShared'. They use the shared allocator.
* peer_manager_request: no need to use ptr WakuNode.
* waku_thread: moving the 'waitFor' to upper layer.
* waku_thread: `poll()` -> `waitFor sleepAsync(1)` to avoid risk of blocking.
* libwaku: thread-safe "sub-objects" in an inter-thread requests.
When two threads send data each other, that data cannot contain any
GC'ed type (string, seq, ref, closures) at any level.
* Allocating the 'configJson' in main thread and deallocating in Waku Thread.
