chat: don't use incomplete types with signals/slots/Q_INVOKABLE (#2408)

Signed-off-by: Jared Van Bortel <jared@nomic.ai>

gpt4all-chat/network.h

@@ -1,19 +1,18 @@
 #ifndef NETWORK_H
 #define NETWORK_H
 
+#include <QByteArray>
 #include <QJsonValue>
+#include <QList>
 #include <QMap>
 #include <QNetworkAccessManager>
+#include <QNetworkReply>
 #include <QObject>
+#include <QSslError>
 #include <QString>
 #include <QVariant>
 #include <QVector>
 
-class QByteArray;
-class QNetworkReply;
-class QSslError;
-template <typename T> class QList;
-
 struct KeyValue {
     QString key;
     QJsonValue value;