Implement Push/Pull V-Tool, Report All Mixes via M165 R, and full E support

[Glodigit]

Description

• Attempts to implement fast colour changing strategy discovered by Heinz
• Adds M165_report()
  • Use 'M165 R' to report V-tool V0 - Vn with the same codes used as M165, normalised to 100.0%
  • The output is compact so that it can be easily read on a BTT TFT Touchscreen (TFT24 tested)
• Fix to support all 8 extruders
• Fix to prevent crash using G3, and potential overlap with G1 I/J/K axes

Requirements

• #define MIXING_EXTRUDER
• #define DIRECT_MIXING_IN_G1
• #define PUSH_PULL_TOOLCHANGE
• Set 'MIXING_PUSH_PULL_MM' to a suitable retract distance for your hotend

Benefits

• Goal is to be able to change v-tools with less or near-0 purge required, without any GCODE modifications. Push/Pull happens when switching from one virtual tool to another.
• View all V-tool mixes at once.
• Confirm that the correct V-tool mix was set. For example, 'M165 A50 C50 R'
• Allow viewing of V-tools without display.
• Makes it possible to add mixing-extruder auto-detection features to BTT Touchscreen FW (e.g. to address #19502).
• Allows marlin to compile when MIXING_STEPPERS > 6
• Allows use of >= 6 channels with G2/G3 arc support

Images

Configuration tested on Octopus Pro v1.0 + EXP MOT

#define MIXING_EXTRUDER
#define MIXING_STEPPERS 8
#define DIRECT_MIXING_IN_G1
#define PUSH_PULL_TOOLCHANGE