Add get_status() method to screws_tilt_adjust

[theophile]

This is a resubmission of my earlier PR #4634 with additional work to fix the previously identified whitespace issues and to add the required documentation. Here's the explanation from the original PR:

This adds a get_status() method to the screws_tilt_adjust.py module so that gcode macros and menu elements can read the results from the screws_tilt_calculate command. This creates a new printer.screws_tilt_adjust object with two properties:

error: False by default, but True if the screws_tilt_calculate command triggered the "bed level exceeds configured limits" error.
results: Until the screws_tilt_calculate command is run, this is an empty python list. But once screws_tilt_calculate has completed successfully, this is a list containing a python dictionary for each configured bed screw. Each of those dictionaries contains the following keys:

• name: Value is the name of the screw from the config file
• x: Value is the configured X coordinate of the screw
• y: Value is the configured Y coordinate of the screw
• z: Value is the measured Z probe height above the screw
• sign:* Value is either "CW" for clockwise or "CCW" for counter-clockwise
• adjust:* Value is the amount the screw must be adjusted, expressed in the same "time" format as is output in the console. (e.g. 01:15 for one full turn plus a quarter turn)

*The dictionary for the "base" screw does not have the sign or adjust keys because the calculation assumes the base screw will not be adjusted.

I have successfully used this new get_status() method together with a handful of macros, custom menus, display groups, and even a couple of custom glyphs to enable Z-probe bed tramming directly from the printer LCD, with a rudimentary GUI and everything.

[KevinOConnor]

Thanks. In general it seems fine to me. As a high-level comment though, have some keys missing from a dictionary is really annoying to deal with - might be better to just add dummy {'sign': 'CW', 'adjust': '00:00'} values to it.

@matthewlloyd - do you have any comments on this?

-Kevin

[theophile]

Thanks. I went ahead and added the dummy values.

[KevinOConnor]

Thanks.

-Kevin

[pedrolamas]

Hi @theophile, thank you for your work on this!

I didn't notice this PR at the time, but as I am looking into adding support for this in Fluidd and I wonder if instead of suffixing ' (base)' to the base screw, wouldn't it make more sense to have a base boolean property as part of the screw dictionary?

As it stands "base" is an English word yet the names of the screws can be whatever users want to call them, but having a boolean would allow the UI's (and macro's) to better handle the "base" screw.

What do you think of this?