Properties: Add CMAKE_ROLE global property

This property allows scripts to determine whether they're in project
mode, script mode, find-package mode, CTest, or CPack.
Status Job ID Name Coverage
  External
passed ghostflow-check-master

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager