Merge topic 'doc-file-api-omissions' into release-4.1

da73f6b058 Help: Add cxxModuleBmi details missing from file API and release notes
bef17abc09 Help: Add file API fileSet... fields missed in the 3.23 release notes
094436db98 Help: The fileSets item in a codemodel target object is optional
1398ef18c2 Help: Add missing backtrace property to compileCommandFragments
74d70d13cd Help: Fix repeated word in file API docs for sourceFileExtensions

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !10913