It appears that the settings `escoria/esc/command_paths` and
`escoria/main/command_directories` have duplicate purposes.
Unfortunately, they are read in different places, so if you add a
directory to one setting, it will not be present in the other.
Specifically, `ESCCompiler` read from `escoria/esc/command_paths`
while `ESCCommand` and `ESCCommandRegistry` read from
`escoria/main/command_directories`.
As the `COMMAND_PATHS` constant had no references, it seemed more
appropriate to delete.
The `escoria/esc/command_paths` appears to have been set initially in
`project.godot` as part of:
https://github.com/godot-escoria/escoria-demo-game/pull/467
a3c8fe882e