Add a symbol generation file similar to Laravel's Laravel IDE Helper for better IDE support

We generate a flat list of extending classes, this seems like the best way to do it, though laravel's adds methods for some reason. I wrote out everything to put the methods in too, so we can switch easily if it's required in the future.

Not sure how to tie this into grunt due to unfamiliarity, whoever adds this to grunt, please link me to the commit!

Best wishes,
Korvin