Add VERBATIM to CMake custom commands

[Daft-Freak]

Someone thought using a build dir with () in it was a good idea, resulting in a lot of

/bin/sh: -c: line 1: syntax error near unexpected token `('

Adding this magic flag allows them to continue making poor choices fixes that problem.

Also the CMake docs say that this is a good idea:

 Use of VERBATIM is recommended as it enables correct behavior.

[Gadgetoid]

Urge to look up why this isn't the default 😆 sheesh!

Thank you!