Update final screenshots in online help and other places

[jonahgraham]

Please add to this TODO list all the places that need new / final screenshots for CDT 12.

• cdt/NewAndNoteworthy/CDT-12.0.md

  Line 23 in 84d99f2

  TODO: Before release add the final screenshot for the build settings here. I am not including it now because the UI keeps changing.

• doc/org.eclipse.cdt.doc.user/images/cbs_build_settings_tab_cmake.png