Gui: HiDPI fixes for Sketcher (#21098)

* Gui: HiDPI fixes for Sketcher

(cherry picked from commit f043fd7c5c8a6ea003811453165eee7d643f3779)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

(cherry picked from commit 42567ca9fcf2d6bab612715391a7b1911367f75d)

* Apply suggestions from code review

Co-authored-by: Kacper Donat <kadet1090@gmail.com>
(cherry picked from commit 28b52086e9cceae0e095421985479c546df49e44)

* qreal to double

(cherry picked from commit 4434ef18affa082a88390c1e68274de42f7c181e)

* more qreal to double

(cherry picked from commit df15eb6200d4ceab730ca8cf25ab0a90efe1cf41)

* Restore previous code which converted label size to points. View scaling would result in text that is too big.

* Ensure scaled marker size is one of the supported sizes for CIRCLE_LINE otherwise it would default to 7  (or what was set to "MarkerSize" in hGrp)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: Tim Ringenbach <tim.ringenbach@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Kacper Donat <kadet1090@gmail.com>

src/Mod/Sketcher/Gui/ViewProviderSketch.cpp

@@ -3969,6 +3969,16 @@ int ViewProviderSketch::defaultFontSizePixels() const
     return static_cast<int>(metrics.height());
 }
 
+qreal ViewProviderSketch::getDevicePixelRatio() const
+{
+    if (auto activeView = qobject_cast<Gui::View3DInventor*>(this->getActiveView())) {
+        auto glWidget = activeView->getViewer()->getGLWidget();
+        return glWidget->devicePixelRatio();
+    }
+
+    return QApplication::primaryScreen()->devicePixelRatio();
+}
+
 int ViewProviderSketch::getApplicationLogicalDPIX() const
 {
     return int(QApplication::primaryScreen()->logicalDotsPerInchX());