CoreXY + dual Carriage X

[DrumClock]

i, maybe it would work with the upcoming new generic_cartesian kinematics:

New generic_cartesian kinematics (incl. CoreXYU/CoreXYUV, generic IDEX and AWD)

A follow-up from the thread in the PR regarding inverted hybrid corexy kinematics. As per discussion there I went ahead and implemented a new generic_cartesian kinematics class (code available here). This new kinematics class allows one to define in a pretty flexible manner an arbitrary Cartesian-style kinematics. In principle, the regular cartesian, corexy, hybrid_corexy can be defined that way, but more importantly, previously unsupported kinematics such as inverted hybrid_corexy can now be su…