Revert use of OPTIONAL_COMPONENTS in idyntree_handle_dependency
Revert use of OPTIONAL_COMPONENTS in idyntree_handle_dependency

Apparently `OPTIONAL_COMPONENTS` is only supported by `find_package` in `MODULE` mode, not in `CONFIG MODE`.
robotology/idyntree,robotology/idyntree,robotology/idyntree,robotology/idyntree,robotology/idyntree