Code formatting

Context

issue : aidge#6

• Update readme

.gitlab/ci/code_quality/cpp.gitlab-ci.yml

+include:
+  - local: '/.gitlab/ci/default.gitlab-ci.yml'
+
+code_quality:static_analysis:cpp:
+  stage: code_quality
+  extends: 
+    - .rules:code_quality:cpp
+  tags:
+    - static_analysis
+  before_script : 
+    - !reference [.retrieve_deps:apt, script]
+    - apt-get install -y cppcheck python-is-python3
+    - python -m pip install Pygments
+    - python -m pip install -U cppcheck_codequality
+
+  script:
+    - mkdir -p $CI_COMMIT_REF_NAME
+    - cppcheck -j 4 --enable=all --inconclusive --force --xml --xml-version=2 . 2> cppcheck-result.xml
+    - cppcheck-htmlreport --file=cppcheck-result.xml --report-dir=$CI_COMMIT_REF_NAME --source-dir=src
+    - cppcheck-codequality --input-file=cppcheck-result.xml --output-file=cppcheck.json
+    - mkdir -p public/cpp
+    - mv $CI_COMMIT_REF_NAME public/cpp/
+  artifacts:
+    paths: 
+      - public
+    reports:
+      codequality: cppcheck.json
+
+code_quality:coverage:ubuntu_cpp:
+  stage: code_quality
+  needs: ["build:ubuntu_cpp"]
+  extends:
+    - .build:variable:aidge_install 
+    - .rules:code_quality:cpp
+  tags:
+    - docker
+  before_script:
+    - !reference [.retrieve_deps:apt, script]
+    - apt-get install -qq -y gcovr
+  script:
+    - cd $BUILD_DIR
+    - ctest --output-on-failure
+    # HTML report for visualization
+    - gcovr --html-details --exclude-unreachable-branches -o coverage.html --root ${CI_PROJECT_DIR} --filter '\.\./include/' --filter '\.\./src/'
+    # Coberta XML report for Gitlab integration
+    - gcovr --xml-pretty --exclude-unreachable-branches --print-summary -o coverage.xml --root ${CI_PROJECT_DIR} --filter '\.\./include/' --filter '\.\./src/'
+  coverage: /^\s*lines:\s*\d+.\d+\%/
+  artifacts:
+    name: ${CI_JOB_NAME}-${CI_COMMIT_REF_NAME}-${CI_COMMIT_SHA}
+    expire_in: 2 days
+    reports:
+      coverage_report:
+        coverage_format: cobertura
+        path: $BUILD_DIR/coverage.xml
+
+        
+code_quality:code_format:cpp:
+  stage: code_quality
+  extends: .rules:format_check:cpp
+  tags:
+    - docker
+  before_script:
+    - !reference [.retrieve_deps:apt, script]
+    - apt install -y -qq wget git
+    - wget https://apt.llvm.org/llvm.sh
+    - chmod u+x llvm.sh
+    - ./llvm.sh 18
+    - apt-get install -y -qq clang-format-18 software-properties-common lsb-release
+  script: 
+    - echo "Ensuring that all cpp files modified in previous commit are correctly formatted. If not, this job will fail."
+    - modified_files=$(git diff --name-only HEAD origin/dev) # change "dev" to $CI_DEFAULT_BRANCH when whole codebase is formatted
+    - modified_CXX_files=$(echo $modified_files | grep ".h$\|.c$\|.hpp$\|.cpp$\|.cu$" || true )
+    - >
+      if [[ -n $modified_CXX_files ]]; then
+        CXX_files_to_format=$(clang-format-18 --style=file:.clang-format --dry-run $modified_CXX_files)
+        CXX_files_to_format=$(( $CXX_files_to_format != "" ? $CXX_files_to_format : ""))
+        echo "CXX FILES TO FORMAT :"
+        echo "$CXX_files_to_format"
+      fi
+    - >
+      if [[ "$CXX_files_to_format" != "" ]]; then
+        echo "You pushed unformatted files, setup a code formatter before pushing your code."
+        echo "For more informations about code formatting head to the dedicated wiki page :"
+        echo "https://gitlab.eclipse.org/groups/eclipse/aidge/-/wikis/code-quality-:-formatting-&-linting"
+        exit 1
+      else 
+        echo "No files to format, congratulations!"
+      fi