Use the connecting straight tracks even if not exactly parallel - allow
an error margin configurable in ADVANCED_CFG (default 1 degree). Also
be less strict about end point matching and use the width of the track
as the criteria to determine suitability.
Finally, delete any short lengths of track at the end of the operation
and amend the arc end points to keep connectivity.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/7967
235688e459