cmake: Be able to prevent the found header files from being included in project searches/list of files which can be opened

cmake: Be able to prevent the found header files from being included in project searches/list of files which can be opened. Currently it will scan from the project root to find any header files and list them as grayed out. However if there are a lot of third party includes that are inside that root then it will include all of those which can have a hit on performance. Particularly when using CTRL+K to open a file, it will list all of them as well.

Therefore having an option to disable this feature would be nice to have.