This PR fixes a lot of warnings from Clang-Tidy (or suppresses them in case of false positives). Furthermore, GitHub actions have been updated.

Details:

Clang-Tidy warnings

The following warnings are currently suppressed to have a green CI. They need to be addressed at some point:

-portability-template-virtual-member-function,
-bugprone-use-after-move,
-hicpp-invalid-access-moved,

Suppressed the following warnings:

• boost-use-ranges: we don't want to rely on Boost
• modernize-use-designated-initializers: designated initializers are a C++20 feature
• modernize-use-ranges: ranges are a C++20 feature

Update GitHub actions

• update all workflows to use the newer versions actions/upload-artifact@v4, actions/checkout@v4, github/codeql-action/init@v3, peaceiris/actions-gh-pages@v4
• remove unsupported macos-11 image; the following Xcode versions are no longer tested in the CI: '11.7', '12.4', '12.5.1', '13.0'
• add macos-13 image to test Xcode versions '14.2', '14.3', '14.3.1', '15.0.1', '15.1', '15.2'
• add macos-14 image to test Xcode versions '15.3', '15.4'
• add macos-15 image to test Xcode versions '16.0', '16.1'
• test GCC versions '4.8', '4.9', '5', '6' on json-ci image as these versions are no longer work on the respective gcc images (checkout fails)
• add tests for GCC versions '13', '14'
• add tests for Clang versions '16', '17', '18', '19'
• update REAMDE with table of compilers/OS used in the CI