[ntcore] Various NT4 fixes (#4474)

* TopicListener: Fix Add() return values
* Update PubSubOption poll storage documentation
* Update NetworkTableEntry::GetValue() doc
* Add documentation regarding asynchronous callbacks
* Unpublish entry: set publisher to nullptr
* Implement ValueListenerPoller default constructor
* Remove SetNetworkIdentity, make parameter to StartClient
* URI-escape client ID, improve error message
* Add connected message with client id; also improve disconnected message a bit
* Handle SetServers either before or after StartClient
* Fix client use-after-free; also delay reconnect after disconnect to rate limit
* Don't re-announce to already subscribed client; we especially don't want to send the last value again
* Always accept in-order sets, only use timestamp for tiebreak
* Fix LocalStorage::StartNetwork race
* Remove unused/unimplemented function

Also:
* [glass] Remove debug print
* [glass] Fix mpack string decoding
* [cameraserver] Fix up startclient

cameraserver/multiCameraServer/src/main/native/cpp/main.cpp

@@ -183,7 +183,7 @@ int main(int argc, char* argv[]) {
     ntinst.StartServer();
   } else {
     fmt::print("Setting up NetworkTables client for team {}\n", team);
-    ntinst.StartClient4();
+    ntinst.StartClient4("multicameraserver");
     ntinst.SetServerTeam(team);
   }