Drawer now affected by theme, consistent with the rest of the active elements.

TODO: Add hover for desktop

This is a small experiment into creating a custom theme for QGC.

Restore QGC to its normal UI layout (buttons on toolbar)

* Make MainToolbarIndicators reusable by other views
* Change to font based ratio sizing

Map control use different border color based on map type

Use default font wherever possible. Where that doesn’t work, use
ScreenTools::dpiAdjustPointSize.

Tool bar buttons now use QGCButton as base to inherit hover mode fix.
Made QGCButton.showHightLight into a public property so I could use it as a trigger for repainting the chevron button.