[Client] Show latency in status bar and server tab indicator (#7154)

* [Client] Show live connection latency in the status bar

Add a permanent status-bar label fed by ConnectionController's
pingStatsUpdated: shows the latest round-trip time, hides while
disconnected or without samples, and carries a tooltip with
Last/Median/95th percentile/Maximum over the rolling sample window
(mirrored into the accessible description). The server tab gets the
same stats as its tooltip.

Took 2 minutes

Took 2 minutes

Took 1 minute

Took 48 seconds

Took 25 seconds

Took 4 minutes

* [Client] Graph connection latency history in the status bar

Add LatencyGraphWidget, a size-agnostic bar sparkline over the rolling
sample window: heights scale to the window's own range while colors map
onto an absolute quality ramp, so a steady good ping stays green. Embed
it in the new LatencyStatusWidget together with the textual ping
readout and feed both through ConnectionController's forwarded signals;
the whole area hides while disconnected or without samples.

Took 9 minutes

Took 14 seconds

* [Client] Show latency details when clicking the ping display

Clicking the status bar ping area opens a popup with a larger instance
of the latency graph plus the numeric statistics, selectable and
mirrored into the accessible name. Qt::Popup closes it on any outside
click; contents refresh live while open.


Took 33 seconds

* Fixup from core commit

Took 6 minutes

Took 5 seconds

Took 5 minutes

* Lint.

Took 12 minutes

* Consolidate.

Took 6 minutes

---------

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

cockatrice/src/interface/window_main.cpp

@@ -19,6 +19,7 @@
  ***************************************************************************/
 #include "window_main.h"
 
+#include "../client/latency_status_widget.h"
 #include "../client/network/update/client/client_update_checker.h"
 #include "../client/network/update/client/release_channel.h"
 #include "../client/settings/cache_settings.h"
@@ -56,6 +57,7 @@
 #include <QDesktopServices>
 #include <QFile>
 #include <QFileDialog>
+#include <QLabel>
 #include <QMenu>
 #include <QMenuBar>
 #include <QMessageBox>
@@ -535,6 +537,12 @@ MainWindow::MainWindow(QWidget *parent)
             [this](bool show) { statusBar()->setVisible(show); });
     statusBar()->setVisible(SettingsCache::instance().userInterface().getShowStatusBar());
 
+    latencyStatus = new LatencyStatusWidget(this);
+    statusBar()->addPermanentWidget(latencyStatus);
+
+    connect(connectionController, &ConnectionController::pingStatsUpdated, latencyStatus,
+            &LatencyStatusWidget::updateData);
+
     connect(&SettingsCache::instance().shortcuts(), &ShortcutsSettings::shortCutChanged, this,
             &MainWindow::refreshShortcuts);
     refreshShortcuts();