3.4 NOCHANGE: hangprinter: simplify things by turning unrolled stuff into loops

[jtimon]

This is in preparation of potentially supporting more anchors for different hangprinter setups than the "standard" one, (4 anchors, 3 base anchors plus one on top for stability).
pinging @tobbelobb to have an opinion on the changes if possible.

There is no functional change in this PR (unless it has bugs).

[tobbelobb]

I like this change. The unrolls were only a coincidence, I had no reason to unroll. I like all changes that bring us closer to Hangprinter's number of axes being a config.g variable.

I'd like to see a test on hardware or at least some kind of typo-safeguarding test before merge.

[jtimon]

I pushed a new version with improvements from the feedback and testing.

I tested M669 and M666 without parameters, but I still didn't manage to test HangprinterKinematics::WriteCalibrationParameters, how do I test that?

I also didn't test any of the modified parts related to CAN/Odrive. And I won't manage to test anytime soon, but at the same time those changes seem quite simple and inoffensive.

Testers on that front are very welcomed. For this PR, you just need a working hangprinter, upgrade to this build, test everything you normally do keeps working, report and go back to your previous working .bin, just in case.

Some parts can be tested without a hangprinter too, but we really don't want to break any of the current working hangprinters before we add any new experimental functionality.

[tobbelobb]

HangprinterKinematics::WriteCalibrationParameters, how do I test that?

I think ran M500 and inspected the resulting sys/config-override.g manually. You could also do a M501 to make the machine try to read and load the stored parameters. Remember to delete sys/config-override.g when done.

Testers on that front are very welcomed. For this PR, you just need a working hangprinter, upgrade to this build, test everything you normally do keeps working, report and go back to your previous working .bin, just in case.

I'll see if I can put it on my machine within a couple of weeks. Will report back here.

[jtimon]

Thank you. But, actually, perhaps for your testing you should wait for the rebased version of this PR, since more things changed than I expected. Some of the changes here may no longer needed. I will post a reference here to the new one and close this one when it's done.

[jtimon]

Closing in favor of #597