MID-YEAR Maintenance release I

This is not the latest version, to get the latest version go here: https://github.com/mriscoc/Ender3V2S1/releases/latest

What's new in this release

Advanced Settings menu reorganization
Custom G-code C10 to mark a G-code file as a configuration file to avoid confirm to print and print done dialogs.
Custom G-code C851 Mn ; Set Multiple Probing
Fix bug: forbid multiple probing = 1
Custom G-code C851 can be used to change the manual Z-offset for versions without probe
De-bounce rotary encoder when a parameter is edited
Allows to set the Z height after Z home for Manual Mesh version.
Re-enabled ADAPTIVE_STEP_SMOOTHING
Media Update (auto-mount) Enable/Disable menu item
Support up to 6 Preheat settings (needs own compile)
Support for Model predictive temperature control "MPC" (needs own compile)
Refactoring Print File menu for performance and stability
Enhanced Active mesh leveling indicator
Fix drawing bug in select file menu: #241
Fix: Z at right edge out of mesh border is being overcompensated if UBL is active

From Last Marlin bugfix 2.1.x