[Feature Request]: Consistent include directory when used as subproject or installed

[Maetveis]

It is quite popular in CMake projects to depend on an upstream project by including it into the build system of the dependent project, for example using FetchContent.

Unfortunately if consumed like this, the recommended way of including the header files from the project can't work:

#include <level_zero/ze_api.h> // Can't work, the include folder does not have a parent named level_zero

Related to: #57