Updated option on M600 change filament gcode to charge filament until user press the button.

Sending the M600, marlin does:
1. FILAMENTCHANGE_FIRSTRETRACT
2. FILAMENTCHANGE_ZADD
3. Goes to ILAMENTCHANGE_XPOS and FILAMENTCHANGE_YPOS
4. FILAMENTCHANGE_FINALRETRACT
5. Extrude until user click the button on LCD panel ->implemented here
6. Goes to the last position to continue printing
7. Add FILAMENTCHANGE_FIRSTRETRACT