feat: improve config v3 (#4015)

* remove --mode from the CLI
* move WakuMode to the messaging layer
* expose store backend (db url, max connections) and a remote store node on the messaging surface
* wakunode2 with no flags now runs as a full service node (store still opt-in)
* add rateLimitMessagesPerEpoch
* channel rate-limiting auto-enables if epochPeriodSec or messagesPerEpoch is set
* fix JSON conf parser to be generic (works over all config types)
* messaging config = mode + preset + messagingOverrides + channelsOverrides
* add full messaging plus selective kernel config options to MessagingClientConf
* mode (Core/Edge) expands to kernel protocol flags in the messaging layer
* create_node parses the messaging config, drops the flat WakuNodeConf JSON entrypoint
* wire channelsOverrides (segmentation/SDS/rate-limit) into channel creation
* fix liblogosdelivery.h comments and README for the new config shape
* messaging conf tests: switch names, reject-unknown, set-twice, field->kernel
* add kernel log-level, log-format, nodekey to the messaging surface
* Port 0 (ephemeral) default for messaging entry points
* KernelConf alias for WakuNodeConf
* rewrite the FFI examples to the new config shape
* C/C++ examples use preset status.prod
* drop operator-only confs from the examples
* remove duplicate tests & misc test fixes
* Delete p2pReliability from Kernel (Waku) resolver and config (keep preset definition)
* Delete NodeConfig API (deprecation completed by p2pReliability removal from kernel)
* Rename test_messaging_conf.nim to test_conf.nim (tests Logos Delivery config in general)
* Rename messaging_conf_json.nim to logos_delivery_conf_json.nim
* Add logos_delivery_conf.nim (defines LogosDeliveryConf aggregate)
* misc docs/comments cleanups

examples/python/waku.py

@@ -55,15 +55,16 @@ args = parser.parse_args()
 
 # The next 'json_config' is the item passed to the 'logosdelivery_create_node'.
 json_config = "{ \
-                \"host\": \"%s\",   \
-                \"port\": %d,       \
-                \"key\": \"%s\",    \
-                \"relay\": %s      ,\
-                \"logLevel\": \"DEBUG\" \
+                \"mode\": \"Core\", \
+                \"messagingOverrides\": { \
+                    \"listen-address\": \"%s\", \
+                    \"tcp-port\": %d,           \
+                    \"nodekey\": \"%s\",        \
+                    \"log-level\": \"DEBUG\"    \
+                } \
             }" % (args.host,
                   int(args.port),
-                  args.key,
-                  "true" if args.relay else "false")
+                  args.key)
 
 callback_type = ctypes.CFUNCTYPE(None, ctypes.c_int, ctypes.c_char_p, ctypes.c_size_t)