Improve Typing for better PHPStan/IDE support

[djfhe]

Not sure if this is possible, but we should try to improve typings to avoid error like this:

Typing the closure returned from createAddColumnClosure in src/Schema/MagellanBlueprint.php would maybe already help here.

[saibotk]

I cannot reproduce this on 2.0, i believe you are on version 1.x?
Also, note that these methods are already deprecated and we now recommend using the Laravel native geometry and geography functions