[Extra] Add a small tool to find orphan local scripts

[dwatteau]

An idea for an extra tool…

1. Extract the resources of the current game with scummrp -o
2. In each room, descumm each script
3. List every local script (LSCR) being called in this room
4. Compare this to the list of available local scripts in that room
5. If some local scripts are never called: print them, for further analysis.

For example, in MONKEY2, I discovered that LFLF_0075/ROOM/ENCD never starts the LFLF_0075/ROOM/LSCR_0201 script, which contains extra sentences from Wally (was it an oversight or a leftover, that's another question).

This small tool would help finding other potentially "forgotten" scripts in the games.