* [cmake] Adding GSL_INSTALL option

Not all consumers of GSL automatically want to have this install logic.

It's good practice to gate install logic behind an option.
For an example look at magic_enum:
https://github.com/Neargye/magic_enum/blob/master/CMakeLists.txt

If the client wants to install GSL they still can. But they should ask
for it by overriding GSL_INSTALL.

* Update cmake/guidelineSupportLibrary.cmake

added nl@eof

* Update CMakeLists.txt

* Update CMakeLists.txt

Co-authored-by: Juan Ramos <juanr0911@gmail.com>
Co-authored-by: Jordan Maples [MSFT] <49793787+JordanMaples@users.noreply.github.com>