all calls to qsTr are done, if I didn't forget anything,
on the PX4 QML files.

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

Add scroll height indicators to Flickable

Also adjusting text layout while at it.

Everything is now based off of default font pixel size

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

Moved update canvas signal to perspective load instead of hooking it to the paint event.
Added an "S" as the unit for the number of cells fact (as in 4S).

Added "Advanced Settings" check box.

Created new ScreenTools exported control for QML code to obtain screen DPI factor to be used for computing font point sizes. This code used to be in the tool bar code and now is available to all QML widgets.
Moved global mouse position tool into ScreenTools as I felt it would be a place to collect these sort of functionality.
Replaced Tree used in the Safety Component from a PNG file to a SVG file as the PNG was not scaling up properly.