Adjust .clang-format to match style used in readonly_graph.h

[Tradias]

VSCode

1. Install xaver.clang-format extension (if you already have the clangd extension then you can skip this step)
2. Open keyboard shortcuts (press ctrl + k followed by ctrl + s)
3. Search for Format Document, change the keybind as desired. Ctrl + alt + f seems to be a common bind, it also works on https://godbolt.org/
4. Open any header or cpp file and press the keybind. It will ask you to configure a formatter, select xaver.clang-format. Alternatively put this into user settings.json:

    "[cpp]": {
        "editor.defaultFormatter": "xaver.clang-format"
    },
    "[c]": {
        "editor.defaultFormatter": "xaver.clang-format"
    },

Pre-commit hook

Since this is a multi language project you will probably want to set up a more sophisticated hook that formats and lints c++, python and java. https://pre-commit.com/ might be able to do that but I have not looked into it. For a pure CMake-based hook for C++ see https://github.com/Tradias/asio-grpc/blob/master/cmake/AsioGrpcInstallGitHooks.cmake for example.