Add KAMP for 3KE

[michael-fritzsch]

Background

KAMP (Klipper Adaptive Meshing & Purging) is currently not available for installation via Creality Helper Script for Ender-3 V3 KE printers. This PR adds KAMP for Ender-3 V3 KE.

Changes

• Add KAMP item to install/remove menu
• Add 3KE-specific START_PRINT and END_PRINT g-code macros
• Add 3KE-specific classic purge line g-code (that's the way how I purged before; happy to change this if anyone has a better method for classical purging)
• Change default purge amount to 30mm, following the default value used in the official KAMP repo

Tests

This PR has been tested on a Ender-3 V3 KE as follows:

• Orca slicer has been configured as defined in the wiki (especially start/end gcode): https://guilouz.github.io/Creality-Helper-Script-Wiki/slicers/orcaslicer/
• Classic purge line
• Adaptive purge line
• No bed mesh
• Full bed mesh
• Adaptive bed mesh