High DPI resolutiuon scaling for QtScope

[aschester]

https://doc.qt.io/qt-5/highdpi.html

Can set Qt::AA_EnableHighDpiScaling and Qt::AA_UseHighDpiPixmaps, but this doesn't scale text. Other options may scale non-fixed size widget items (but not fixed size, of which there are a few...) and text but may clip text which doesn't fit into fixed-size widgets. The latter can be done by setting QT_SCALE_FACTOR >= 1 and launching the application. Can we do something similar, automaticall from within the program after its running but before it displays any graphics?

[aschester]

Removing the fixed size works up to a point. The channel spin box is very slightly resized when its range is configured on boot and as a result can appear as hidden because the main widget window is not resized correctly. Various attempts at nested adjustSize calls to autosize the widget don't seem to fix the problem. Initializing the spin box range to 0, 99 in the acq toolbar constructor is a workaround that ensures the spin boxes are created with enough space to accommodate two digits each.

[aschester]

Issue is now part of #146