find_package: Extend module mode with FIND_ROOT_PATH options
Currently the find_package() function has two modes: MODULE and CONFIG. The CONFIG mode has the capability to change the FIND_ROOT_PATH
behaviour on per-call basis with the following flags:
CMAKE_FIND_ROOT_PATH_BOTH - Search in the order described above. NO_CMAKE_FIND_ROOT_PATH - Do not use the CMAKE_FIND_ROOT_PATH variable. ONLY_CMAKE_FIND_ROOT_PATH - Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.
This flags would as well be nice to have in MODULE context to be able to find easily default modules and override for them the FIND_ROOT_PATH
behaviour.