Revise 'Add trackers' dialog

* Now it allow user to add tracker to different tier.
* The downloaded trackers are now displayed as is (without modifying).
* Now the dialog remember dialog size and last used URL.

Closes #17692.

src/base/bittorrent/trackerentry.h

@@ -30,10 +30,12 @@
 
 #include <libtorrent/socket.hpp>
 
+#include <QtContainerFwd>
 #include <QtGlobal>
 #include <QHash>
 #include <QMap>
 #include <QString>
+#include <QStringView>
 
 namespace BitTorrent
 {
@@ -74,6 +76,8 @@ namespace BitTorrent
         QString message {};
     };
 
+    QVector<TrackerEntry> parseTrackerEntries(QStringView str);
+
     bool operator==(const TrackerEntry &left, const TrackerEntry &right);
 #if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
     std::size_t qHash(const TrackerEntry &key, std::size_t seed = 0);