DPI aware dynamic UI rescaling

[goodboy]

Though #157 seem to fix most lo vs. hi DPI issues, where spawning a UI will configure sizing to where (i.e. the dpi of the source display) it was started, it sure would be nice to be able to have re scaling be automatic even if the UI is moved to another display with a different DPI.

https://forum.qt.io/topic/52296/detect-changing-devicepixelratio seems to have some discussion on this.

Oddly the built-in hi dpi detection reportedly works great on windows and does all this auto-scaling automatically 😂

[goodboy]

https://stackoverflow.com/questions/25761556/qt5-font-rendering-different-on-various-platforms/25929628#25929628 might also be relevant.

[goodboy]

getting closer to this with our new FieldsForm from #205 fwiw.

I think i want to release an ORM system built around Qt +trio + pydantic eventually.