Merge branch 'feature/cut_len_for_header_struct' into 'master'

build: Add trimming PROJECT_VER and PROJECT_NAME vars

See merge request idf/esp-idf!3927

diff --cc docs/en/api-guides/build-system-cmake.rst
Simple merge

diff --cc tools/ci/test_build_system_cmake.sh
Simple merge

diff --cc tools/cmake/idf_functions.cmake
Simple merge