Make corrscope window size dpi-independent, widen window (#238)

Tested on Linux, Wine, and Windows 10.

corrscope/gui/view_mainwindow.py

@@ -52,7 +52,13 @@ class MainWindow(QWidget):
     left_tabs: "TabWidget"
 
     def setupUi(self, MainWindow: QMainWindow):
-        MainWindow.resize(1160, 0)
+        # Multiplying by DPI scale is necessary on both Windows and Linux,
+        # since MainWindow.resize() operates in physical pixels.
+        scale = MainWindow.logicalDpiX() / 96.0
+
+        width = 1280
+        height = 0
+        MainWindow.resize(width * scale, height * scale)
 
         s = LayoutStack(MainWindow)