svx: Cleanup ASCII art and useless comments

Change-Id: I5399362056276f324fd43eda05d3f606dc6f8c71
Reviewed-on: https://gerrit.libreoffice.org/11011
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>