xyzbc-trt-kins (switchkins)

Uses remapped user m codes for kins switch:

  M429: Identity Kinematics
  M428: XYZBC (TCP)
  M430: userk Kinematics

A hal net is required to connect the
analog out pin N, Example (for N=3):

  net :kinstype-select <= motion.analog-out-03
  net :kinstype-select => motion.switchkins-type

Hal Input pins:
  xyzbc-trt-kins.x-offset
  xyzbc-trt-kins.z-offset

X and Z offsets are the offsets from the center
of rotation of the B axis relative to the center
of rotation of the C axis.

Hal Input pins:
  xyzbc-trt-kins.x-rot-point
  xyzbc-trt-kins.y-rot-point
  xyzbc-trt-kins.z-rot-point

X, Y and Z rot-point pins represent the
offsets of the center of rotation of the C axis
relative to the machine absolute zero

Hal Input pins:
  xyzbc-trt-kins.conventional-directions

Pin conventional-directions is false by default. If true,
axis directions follow the conventions as defined
at https://linuxcnc.org/docs/html/gcode/machining-center.html#_rotational_axes