Better logging and use of C++ concepts in C++20.
### Breaking Change
- Changed C++ standard to C++20 ([Issue #105](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/105)).
- Removed the old version of iteration_logger in util module ([Issue #103](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/103)).
- Refactor namespaces ([Issue #104](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/104)).
- Use of C++ 20 concepts ([Issue #104](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/104), [Issue #119](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/119), [Issue #120](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/120), [Issue #123](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/123), [Issue #124](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/124)).
- Change API of integrators ([Issue 130](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/130)).
### Feature
- Modules
- base (new)
- Added concepts ([Issue #103](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/103), ([Issue #104](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/104)).
- logging (new)
- Implemented logging ([Issue #103](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/103), [Issue #116](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/116)).
- util
- Source location in exceptions ([Issue #97](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/97), [Issue #128](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/128)).
- Logging in assertions ([Issue #103](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/103)).
### Miscellaneous
- Build system
- Add option to enable OpenMP ([Issue #110](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/110)).
- Proper configuration of C++ standard libraries ([Issue #127](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/127)).
- Compatibility with libc++ 12 ([Issue #129](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/129)).
- Benchmarks
- Change benchmark library ([Issue #108](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/108)).
- Miscellaneous
- Add GitLab Issue templates ([Issue #109](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/109)).
- Add .gitmessage for writing Git commit messages ([Issue #109](https://gitlab.com/MusicScience37/numerical-collection-cpp/-/issues/109)).