Add navigation to artists from tracks

I'm not to happy about the C++ sides. If anyone from the future finds
this commit with "git blame" while debugging this code: I apologise

core/src/jellyfin.cpp

@@ -54,6 +54,7 @@ void JellyfinPlugin::registerTypes(const char *uri) {
     qmlRegisterUncreatableType<ViewModel::User>(uri, 1, 0, "User", "Acquire one via UserLoader or exposed properties");
     qmlRegisterUncreatableType<EventBus>(uri, 1, 0, "EventBus", "Obtain one via your ApiClient");
     qmlRegisterUncreatableType<WebSocket>(uri, 1, 0, "WebSocket", "Obtain one via your ApiClient");
+    qmlRegisterUncreatableType<ViewModel::NameGuidPair>(uri, 1, 0, "NameGuidPair", "Obbtain one via an Item");
     qmlRegisterUncreatableType<ViewModel::MediaStream>(uri, 1, 0, "MediaStream", "Obtain one via an Item");
     qmlRegisterUncreatableType<ViewModel::Settings>(uri, 1, 0, "Settings", "Obtain one via your ApiClient");
     qmlRegisterUncreatableType<ViewModel::UserData>(uri, 1, 0, "UserData", "Obtain one via an Item");

core/src/viewmodel/item.cpp

@@ -26,6 +26,9 @@
 namespace Jellyfin {
 namespace ViewModel {
 
+NameGuidPair::NameGuidPair(QSharedPointer<DTO::NameGuidPair> data, QObject *parent)
+    : QObject(parent), m_data(data) {}
+
 Item::Item(QObject *parent, QSharedPointer<Model::Item> data)
     : QObject(parent),
       m_data(data),
@@ -44,6 +47,7 @@ void Item::setData(QSharedPointer<Model::Item> newData) {
 
     if (!m_data.isNull()) {
         connect(m_data.data(), &Model::Item::userDataChanged, this, &Item::onUserDataChanged);
+        updateMediaStreams();
         setUserData(m_data->userData());
     }
 
@@ -77,6 +81,11 @@ void Item::updateMediaStreams() {
     qDebug() << m_audioStreams.size() << " audio streams, " << m_videoStreams.size() << " video streams, "
              << m_subtitleStreams.size() << " subtitle streams, " << m_allMediaStreams.size() << " streams total";
 
+    m_artistItems.clear();
+    const QList<DTO::NameGuidPair> artists = m_data->artistItems();
+    for (auto it = artists.cbegin(); it != artists.cend(); it++) {
+        m_artistItems.append(new NameGuidPair(QSharedPointer<DTO::NameGuidPair>::create(*it), this));
+    }
 }
 
 void Item::setUserData(DTO::UserItemDataDto &newData) {

core/src/viewmodel/itemmodel.cpp

@@ -18,6 +18,8 @@
  */
 #include "JellyfinQt/viewmodel/itemmodel.h"
 
+#include "JellyfinQt/viewmodel/item.h"
+
 #include "JellyfinQt/loader/http/artists.h"
 #include "JellyfinQt/loader/http/items.h"
 #include "JellyfinQt/loader/http/userlibrary.h"
@@ -93,6 +95,14 @@ QVariant ItemModel::data(const QModelIndex &index, int role) const {
     case RoleNames::runTimeTicks:
         return QVariant(item->runTimeTicks().value_or(0));
     JF_CASE(artists)
+    case RoleNames::artistItems: {
+        QVariantList data;
+        auto artists = item->artistItems();
+        for (auto it = artists.cbegin(); it != artists.cend(); it++) {
+            data.append(QVariant::fromValue(new NameGuidPair(QSharedPointer<DTO::NameGuidPair>::create(*it), const_cast<ItemModel *>(this))));
+        }
+        return data;
+    }
     case RoleNames::isFolder:
         return QVariant(item->isFolder().value_or(false));
     JF_CASE(overview)

core/src/viewmodel/playlist.cpp

@@ -18,6 +18,8 @@
  */
 #include "JellyfinQt/viewmodel/playlist.h"
 
+#include "JellyfinQt/viewmodel/item.h"
+
 namespace Jellyfin {
 namespace ViewModel {
 
@@ -47,6 +49,7 @@ QHash<int, QByteArray> Playlist::roleNames() const {
     return {
         {RoleNames::name, "name"},
         {RoleNames::artists, "artists"},
+        {RoleNames::artistItems, "artistItems"},
         {RoleNames::runTimeTicks, "runTimeTicks"},
         {RoleNames::section, "section"},
         {RoleNames::playing, "playing"},
@@ -83,6 +86,16 @@ QVariant Playlist::data(const QModelIndex &index, int role) const {
         return QVariant(rowData->name());
     case RoleNames::artists:
         return QVariant(rowData->artists());
+    case RoleNames::artistItems: {
+        QVariantList result;
+
+        auto items = rowData->artistItems();
+        for (auto it = items.cbegin(); it != items.cend(); it++) {
+            result.append(QVariant::fromValue(new NameGuidPair(QSharedPointer<DTO::NameGuidPair>::create(*it), const_cast<Playlist *>(this))));
+        }
+
+        return result;
+    }
     case RoleNames::runTimeTicks:
         return QVariant(rowData->runTimeTicks().value_or(-1));
     default: