[Network] Add a configured QNetworkAccessManager factory (#7628)

* [Network] Add a configured QNetworkAccessManager factory

Every HTTP caller built its own QNetworkAccessManager, so the system proxy
and a transfer timeout were easy to omit. Add NetworkManagerFactory::create()
as the single place that applies the process-wide proxy configuration and a
transfer timeout, and use it at all 14 construction sites.

Per-site settings such as disk caches and manual redirect policies stay with
their callers.

* [Tests] Link libcockatrice_network into the tests that compile its headers

release_channel.cpp and card_picture_loader_worker.cpp now include
libcockatrice/network/network_manager.h, but the test targets that compile
them only linked libcockatrice_settings, so the include directory never
reached them and every platform failed with "file not found":
loader_local_matching_test and picture_loader_benchmark_test.

libcockatrice_network is an INTERFACE library, so linking it costs these
targets nothing but hands over the include path.

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/client/network/interfaces/deck_stats_interface.cpp

@@ -20,11 +20,12 @@
 #include <libcockatrice/card/database/card_database_manager.h>
 #include <libcockatrice/deck_list/deck_list.h>
 #include <libcockatrice/deck_list/tree/deck_list_card_node.h>
+#include <libcockatrice/network/network_manager.h>
 #include <version_string.h>
 
 DeckStatsInterface::DeckStatsInterface(QObject *parent) : QObject(parent)
 {
-    manager = new QNetworkAccessManager(this);
+    manager = NetworkManagerFactory::create(this);
     connect(manager, &QNetworkAccessManager::finished, this, &DeckStatsInterface::queryFinished);
 }
 

cockatrice/src/client/network/interfaces/tapped_out_interface.cpp

@@ -26,11 +26,12 @@
 #include <libcockatrice/card/database/card_database_manager.h>
 #include <libcockatrice/deck_list/deck_list.h>
 #include <libcockatrice/deck_list/tree/deck_list_card_node.h>
+#include <libcockatrice/network/network_manager.h>
 #include <version_string.h>
 
 TappedOutInterface::TappedOutInterface(QObject *parent) : QObject(parent)
 {
-    manager = new QNetworkAccessManager(this);
+    manager = NetworkManagerFactory::create(this);
     connect(manager, &QNetworkAccessManager::finished, this, &TappedOutInterface::queryFinished);
 }
 

cockatrice/src/client/network/update/card_spoiler/spoiler_background_updater.cpp

@@ -27,6 +27,7 @@
 #include <functional>
 #include <libcockatrice/card/database/card_database.h>
 #include <libcockatrice/card/database/card_database_manager.h>
+#include <libcockatrice/network/network_manager.h>
 #include <libcockatrice/settings/download_settings.h>
 #include <libcockatrice/settings/paths_settings.h>
 #include <tuple>
@@ -56,7 +57,7 @@ void SpoilerBackgroundUpdater::startSpoilerDownloadProcess(QString url, bool sav
 
 void SpoilerBackgroundUpdater::downloadFromURL(QUrl url, bool saveResults)
 {
-    auto *nam = new QNetworkAccessManager(this);
+    auto *nam = NetworkManagerFactory::create(this);
     auto request = QNetworkRequest(url);
     request.setHeader(QNetworkRequest::UserAgentHeader, QString("Cockatrice %1").arg(VERSION_STRING));
     QNetworkReply *reply = nam->get(request);

cockatrice/src/client/network/update/client/release_channel.cpp

@@ -20,6 +20,7 @@
 #include <QVariant>
 #include <QVariantMap>
 #include <QtGlobal>
+#include <libcockatrice/network/network_manager.h>
 #include <optional>
 #include <qnamespace.h>
 #include <qprocessordetection.h>
@@ -62,7 +63,7 @@ std::optional<int> getProductVersionMajor()
 
 } // namespace
 
-ReleaseChannel::ReleaseChannel() : netMan(new QNetworkAccessManager(this)), response(nullptr), lastRelease(nullptr)
+ReleaseChannel::ReleaseChannel() : netMan(NetworkManagerFactory::create(this)), response(nullptr), lastRelease(nullptr)
 {
 }
 

cockatrice/src/client/network/update/client/update_downloader.cpp

@@ -9,10 +9,11 @@
 #include <QNetworkRequest>
 #include <QUrl>
 #include <QVariant>
+#include <libcockatrice/network/network_manager.h>
 
 UpdateDownloader::UpdateDownloader(QObject *parent) : QObject(parent), response(nullptr)
 {
-    netMan = new QNetworkAccessManager(this);
+    netMan = NetworkManagerFactory::create(this);
 }
 
 void UpdateDownloader::beginDownload(QUrl downloadUrl)