Line properties enhancement for line length

It would be very useful if the line properties dialog box geometry could, in addition to displaying the x and y start and end point values (as at present in ver 2.2.0-rc1), also calculate and display:
1. the horizontal and vertical (x and y) differences (delta - vertical and horizontal length),
2. the angle,
3. the actual length of the line.

It would also be very useful if the offset (delta) values could be edited to accurately adjust the length of the line when anchored to either the start point or the end point (this should be selectable). And, perhaps, although less trivial, allow editing of the angle as well!

This first portion should not be a major change to make in the "librecad/src/ui/forms/qg_dlgline" modules.