Re-export NodeInfo at the wire top level

NodeInfo was the only wire-layer message struct still requiring a
submodule import (`from dqlitewire.messages.responses`) at
consumer sites. Re-exporting it at the curated top level closes
the asymmetry with the other public response types and lets the
client layer import it from `dqlitewire` like everything else.

Author: antoineleclair

src/dqlitewire/__init__.py

@@ -221,7 +221,7 @@
     StreamError,
 )
 from dqlitewire.messages.base import Header, Message
-from dqlitewire.messages.responses import sanitize_for_log, sanitize_server_text
+from dqlitewire.messages.responses import NodeInfo, sanitize_for_log, sanitize_server_text
 from dqlitewire.types import WireInput, WireValue
 
 __version__: Final[str] = "0.1.6"
@@ -290,6 +290,7 @@
     "Message",
     "MessageDecoder",
     "MessageEncoder",
+    "NodeInfo",
     "NodeRole",
     "PoisonedError",
     "ProtocolError",