* create FindXXX.cmake modules for added CPM packages
* don't use list(PREPEND) as it unsupported on older CMake versions
* use CMAKE_BINARY_DIR
* ensure CPM.cmake is initialized only once
* import CPM.cmake in modules
* use semicolon as empty command and add test
* remove platform specific test coverage
* only run actions for pushes and prs into master (avoid duplication)
* remove cache test as it's already part of the test suite
* update version
* test cache reuse
