Convert tool: support converting tracks to graphic lines

Description

I have observed that there is no possibility to transform a trace segment into a graphic line or a graphic object. Instead, the opposite possibility exists. Having a graphic line I can change its level and set it to any from graphic ones to copper ones and more.

This possibility would be useful to create, for example, solder mask lines that match perfectly with the relative copper traces for bare parts to decrease the resistance by depositing a layer of tin. A duplicate track and a level change would be enough to achieve this instead of drawing over the whole track with a graphic line.

I hope I have explained.

Steps to reproduce

  1. duplicate a track

  2. with the menu activated with LMB I don't have a command to perform a transformation in a graphic line.

  3. If it were possible I could set the desired level of the graphic line.

  4. It is not often used but when needed it would be very convenient.

KiCad Version

Application: KiCad (64-bit)

Version: (5.99.0-13185-g0dcbfa2b69), release build

Libraries:
	wxWidgets 3.1.5
	libcurl/7.78.0-DEV Schannel zlib/1.2.11

Platform: Windows 10 (build 19043), 64-bit edition, 64 bit, Little endian, wxMSW

Build Info:
	Date: Nov  9 2021 12:00:58
	wxWidgets: 3.1.5 (wchar_t,wx containers)
	Boost: 1.76.0
	OCC: 7.5.0
	Curl: 7.78.0-DEV
	ngspice: 35
	Compiler: Visual C++ 1929 without C++ ABI

Build settings:
	KICAD_USE_OCC=ON
	KICAD_SPICE=ON
Edited by Jon Evans