Refactoring
- File formats are updated with isort and black.
([`187b100`](https://github.com/EBI-Metabolights/metabolights-utils/commit/187b1004332e3fae5fcce3c01a05c3b64b561d83))
- Column add method is defined.
([`428b7ff`](https://github.com/EBI-Metabolights/metabolights-utils/commit/428b7ffae6363298475cb02e8d00009840ceedb8))
- Refactor code to export modules
([`cadbafd`](https://github.com/EBI-Metabolights/metabolights-utils/commit/cadbafdb1fea5f95556a04f1855af287bb2935c0))