`HAVE_CPP_STDLIB` and  `HAVE_GSL` should be auto added when using `-DWITH_STL=ON` with cmake.

**Describe your environment**
Windows, CMake

**Steps to reproduce**
Using `cmake -DWITH_STL=ON ...` to build project.

**What is the expected behavior?**
`HAVE_CPP_STDLIB` and `HAVE_GSL` should be added into `INTERFACE_COMPILE_DEFINITIONS` of exported target `opentelemetry-cpp::api` .

**What is the actual behavior?**
Nothing here.

**Additional context**
