* add system property for cpm_add_subdirectory
* add test case for system property
* lock CMake version in test workflow
* refactor to make SYSTEM an extra config option and update tests
* remove old comment change
* use consistent CMake version and extension for all workflows
* make warning more specific and try to trigger on windows
* another attempt to trigger warning on MSVC
* update readme
* simplify test case and use git tag
* add SYSTEM option to .cmake-format
* forward system arg for source overrides
* enable system implicitly for the single argument syntax
* Use SYSTEM option for FetchContent and add_subdirectory (#441)
* Use SYSTEM option for FetchContent and add_subdirectory
* Add SYSTEM option to syntax and doku
* Update CPM.cmake
* Update .cmake-format
---------
Co-authored-by: Lars Melchior <TheLartians@users.noreply.github.com>
---------
Co-authored-by: Claus Klein <claus.klein@arcormail.de>
* apply clang-format and cmake-format and add style check workflow
* add declare package definition
* add additional public methods and rename internals
* change development verison tag to 1.0.0
* rename internal method
* rename public method
* rename test var
* update copyright and fix comment
* typo
* run fix-format
* fix test function names
