No way to set sprites to blank/empty?

I wanted to do an effect where the camera pans through the courtroom but the characters are absent; however, it appears the `sprite` command doesn't have a way to make a given sprite position be blank. We can show/hide the witness stand and benches via the `hide` command, but not *just* the characters.

This should be an easy fix, I think - just need to add a hardcoded option to the handling of the `sprite` command in `ace_attorney_scene.py` around line 676.

Open ace_attorney_scene.py around line 676 and inspect how the sprite command handles character positions. Add the requested blank or empty option for an individual character position without hiding the witness stand or benches. Done means a scene can pan through the courtroom with selected characters absent while other elements remain visible.

Written by the indexing model from the issue text.