QtCreator CMake configuration form cluttered with STATIC cache variables

When in `cmake -E server` mode, Qt Creator is displaying the contents of `STATIC` cache variables like `<target>_LIB_DEPENDS`, `<project>_SOURCE_DIR`, etc in the Projects : CMake configuration form. Like `INTERNAL`, these are not shown in cmake-gui (even with Advanced checked).

It looks like qt-creator shows STATIC items along with the basic configuration, and INTERNAL along with the advanced items, which makes a pretty cluttered list. Handling CMakeConfigItem::STATIC the same way CMakeConfigItem::INTERNAL is handled in CMakeBuildConfiguration::completeCMakeConfiguration would be a good start, though really neither of these is meant to show at all in GUIs.