When adding colors to length tuner, we depend on the window background
color, which can be set by the user, resulting in an unreadable text.
This uses the HSL conversion to detect which shade it should use for the
coloring.
Also adds test cases for round-trip HSL and HSV conversion
Fixes: lp:1814530
* https://bugs.launchpad.net/kicad/+bug/1814530
Use standard Magnetize() to handle grid and magnetic pads.
Use the standard menu from PCB_TOOL. Delegating the menu to
the SELECTION_TOOL just caused grief.
Also brings clients (such as Position Relative To) into line,
and implements better Cancel behaviour.
Also improves visibility of modal status messages:
- moves Select Anchor message from status bar to popup
- moves Select Reference message from dialog to popup
Fixes: lp:1786727
* https://bugs.launchpad.net/kicad/+bug/1786727
Jeff Young
Seth Hillbrand
Maciej Suminski
decimad
Tomasz Włostowski