Add M118 messages

[lethuer]

I'm using an artillery genius printer and your addin was modified by @b-morgan to additionally send M118 statements for "time left" and "data left" in a format I need to update my tft of the printer.

M118 P0 A1 action:notification Time Left XXhYYmZZs
-> Updates Time Left Field
M118 P0 A1 action:notification Data Left XX/YY
-> Updates Percentage Field + Progress Bar

Only a few changes are made in file: "init.py"
You can find it attached: m73progress.zip
Also I included this in a version based on 0.2.1 which you can directly install to OctoPrint: OctoPrint-M73Progress-0.2.1-M118.zip

My test results are documented here: https://community.octoprint.org/t/tft-percentage-progress-not-updatet-m73/57420/27?u=lethuer
My proposal is to insert a checkbox in the plugin and if checked to insert M118 messages in the format like shown above.

Additionally I would like if it would be possible to insert layer informations in this format:

M118 P0 A1 action:notification Layer Left XX/YY
-> Updates Layer Left Field

Therefore the slicer (in my case Cura 5.6.0) provides layer information in the gcode:

;LAYER_COUNT:85
;LAYER:1

Plugin "DisplayLayerProgress" already uses this information and adds M117 messages to the gcode while uploading to octoprint:
https://github.com/OllisGit/OctoPrint-DisplayLayerProgress/wiki/How-does-the-plugin-works

[jounathaen]

I'm in the same situation and have created a fork of this OctoPrint plugin that creates support for this and the other features necessary to have the best experience with the TFT: https://github.com/jounathaen/octoprint_btt_touch_support

Happy for any feedback!