[Icons] Migrate UI glyphs to palette-token SVGs (#7595)

* [Icons] Migrate UI glyphs to palette-token SVGs

Runtime inversion is not a theming system: it rotates hue, breaks duotone art
and mishandles alpha, and a QPixmap snapshot cannot follow a palette change.
Redraw the top-level UI glyph set on a 24x24 grid with `currentColor` as the
paint token, drop Inkscape/Sodipodi cruft, and delete the icons whose metaphor
was duplicated (cogwheel/gear -> settings, scale_balanced -> scales,
update.png -> reload).

Load the glyphs through `loadThemedIcon` so the engine resolves the token from
the palette on every request, and let `themePixmap` use the same resolution for
one-shot pixmaps. `loadColorAdjustedPixmap` is gone; every caller now keeps a
QIcon, which `SettingsButtonWidget::setButtonIcon` accepts instead of a QPixmap.

Content art (mana, counters, countries) keeps its authored colors.

Add a render test covering aspect ratio, palette flips, icon modes and
high-DPI pixmaps.

* [Tests] Keep the icon render test QApplication alive until exit

Creating it as a function-local static tears it down before Qt's library statics
at exit, and libQt6Network then runs QObject destructors against freed memory —
a SEGV the sanitizer leg reports after the tests have already passed. Leak the
application instead, the usual pattern for a test binary.

* [Icons] Render lock and dropdown glyphs through the icon engine

Both generators rendered the sentinel SVG to a fixed height x height pixmap
at DPR 1. The pre-migration path rendered larger and let QIcon scale it, so
on a 2x display the games-list lock (13px) and the banner dropdown arrow
(24px) came back crisp; the new path hands the widget a DPR-1 bitmap that
gets upscaled and blurred.

- The games list asks the themed engine for `icons/lock` directly, so the
  item view paints it at the device pixel ratio and the lock also follows
  HighlightedText on a selected row.
- The dropdown goes through `loadThemedIcon(...).pixmap(size, dpr)`, which
  keeps the glyph's aspect ratio and renders at the requested ratio.
- LockPixmapGenerator has no consumer left, so it and its cache are gone.

---------

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

cockatrice/src/interface/widgets/dialogs/dlg_connect.cpp

@@ -1,7 +1,7 @@
 #include "dlg_connect.h"
 
 #include "../../../client/settings/cache_settings.h"
-#include "../../pixel_map_generator.h"
+#include "../../theme_icon.h"
 #include "../server/handle_public_servers.h"
 #include "../server/user/user_info_connection.h"
 #include "libcockatrice/utility/macros.h"
@@ -38,7 +38,7 @@ DlgConnect::DlgConnect(QWidget *parent) : QDialog(parent)
     previousHosts = new QComboBox(this);
 
     btnDeleteServer = new QPushButton(this);
-    btnDeleteServer->setIcon(themePixmap(QStringLiteral("icons/remove_row")));
+    btnDeleteServer->setIcon(loadThemedIcon(QStringLiteral("icons/remove_row")));
     btnDeleteServer->setToolTip(tr("Delete the currently selected saved server"));
     btnDeleteServer->setFixedWidth(30);
 
@@ -46,7 +46,7 @@ DlgConnect::DlgConnect(QWidget *parent) : QDialog(parent)
 
     hps = new HandlePublicServers(this);
     btnRefreshServers = new QPushButton(this);
-    btnRefreshServers->setIcon(themePixmap(QStringLiteral("icons/sync")));
+    btnRefreshServers->setIcon(loadThemedIcon(QStringLiteral("icons/sync")));
     btnRefreshServers->setToolTip(tr("Refresh the server list with known public servers"));
     btnRefreshServers->setFixedWidth(30);
 
@@ -121,7 +121,7 @@ DlgConnect::DlgConnect(QWidget *parent) : QDialog(parent)
     updateDisplayInfo(previousHosts->currentText());
 
     btnForgotPassword = new QPushButton(this);
-    btnForgotPassword->setIcon(themePixmap(QStringLiteral("icons/forgot_password")));
+    btnForgotPassword->setIcon(loadThemedIcon(QStringLiteral("icons/forgot_password")));
     btnForgotPassword->setToolTip(tr("Reset Password"));
     btnForgotPassword->setFixedWidth(30);
     connect(btnForgotPassword, &QPushButton::released, this, &DlgConnect::actForgotPassword);