This refactoring allows the user to use the "enter" key to go to the
next field to fill while create a new user

This refactoring construct manually the UI to add new user groups to
allow the binding of the 'enter' key to the validation function.

This is typical for empty databases.

The transformations are applied from the end of the array. Putting the
scaling factor before the translation for the ruler_offset make the 0,0
point of the ruler stable on scale change (otherwise, the 0,0 point
being moved by the ruler_offset value, it's position change on scale change)

Since the image is streched in the svg, we need to take into account
this ratio in the resolution calculation.