Follow-up to #689, breaking up the script autocomplete setting into 3 separate modes:

• Autocomplete using the map's own scripts. This is fast, and these are likely the most relevant scripts to use.
• Autocomplete using all scripts. This is slow, but every option is available.
• (new) Autocomplete using the map's own scripts and the shared scripts in data/scripts and data/event_scripts.s. This can be slow, but not as slow as gathering all scripts, and it gets all the scripts outside the map's own scripts that are likely to be used.