1.Add sync command. Now gcode and dirrectly add time sync command
2.Add support for ceil and floor in placeholder
3.Update change filament gcode for H2D
jira: NONE
Signed-off-by: xun.zhang <xun.zhang@bambulab.com>
Change-Id: I6dd97cbd96bae1c2751c08357ff64947876d7471
(cherry picked from commit c99fcd454c2499b0c0e3ed9402a2182c00a9bffa)