Status bar not getting updated when targets are modified

After modifying CmakeLists.txt file, if a target's name edited/deleted, the status bar showing the default build target's name will not get updated. This results in an error if the user runs "CMake: build", the workaround is to manually update the target from the status bar.

Reproduce the issue by editing a target name in CMakeLists.txt, then inspect the status bar's default-target handling and the CMake: build entry point. Done means the status bar reflects renamed or deleted targets and running CMake: build no longer uses an invalid target.

Written by the indexing model from the issue text.