Add support for precompiled headers

[sean-mcmanus]

CMake has added support for precompiled headers since 3.16 (https://cmake.org/cmake/help/latest/command/target_precompile_headers.html), could cpptools utilize such a feature to speed up compilation?

Originally posted by @sam20908 in #8338

[sean-mcmanus]

This is related to #3628, although that issue doesn't mention support for CMake's support (I assume the CMake Tools extension would have to send us the pch data for us to use and/or we'd have to parse it from the compile_commands.json).

[github-actions]

This feature request is being closed due to insufficient upvotes. When enough upvotes are received, this issue will be eligible for our backlog.

[github-actions]

This feature request has received enough votes to be added to our backlog.