Choosing the drag origin should not be dependent on the snap settings in
pcbnew. Snap settings are sensible when you are designating a target
only. Additionally, when dragging a module, we do not want the
footprint's pads to be used as targets for snapping.
Fixes: lp:1814402
* https://bugs.launchpad.net/kicad/+bug/1814402
When we draw a path, we usually want to close the path when clicking on
the end of another line. This uses grid helper to ensure this
progression happens as expected.
Distinguish between the snap-from and snap-to items. Previously, we
used the SELECTED or DRAGGED flags but the flagging arcitecture was
inherently fragile. This specifies items directly that should not be
used as snap targets.
Fixes: lp:1802795
* https://bugs.launchpad.net/kicad/+bug/1802795
Many items require precise, non-grid movement. Adding the ability to
flag a non-grid option will permit this behavior.
This is a required precursor commit to fixing lp:1738818 and lp:1771683