Add KlipperPrintStats script [PostProcessingPlugin]

[subdancer]

Description

KlipperPrintStats is a script for the PostProcessingPlugin.
This script will pass slicer info (current layer and total layers) to klipper and the moonraker api.
See https://www.klipper3d.org/G-Codes.html?h=set_print_stats_info#set_print_stats_info
It's also possible to add M117, M118 or even custom commands including variables (see below).

• Available variables:
  ;current_layer;, ;z_height;, ;total_layers;, ;remaining_layers;, ;layer_height;, ;remaining_seconds;,
  ;elapsed_seconds;, ;total_seconds;, ;total_time;, ;total_time_formated;, ;elapsed_time;,
  ;elapsed_time_formated;, ;remaining_time;, ;remaining_time_formated;

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Tested and working nicely

Test Configuration:

• Operating Systems:
  • Linux + Windows

Checklist:

• My code follows the style guidelines of this project as described in UltiMaker Meta and Cura QML best practices
• I have read the Contribution guide
• I have commented my code, particularly in hard-to-understand areas
• I have uploaded any files required to test this change