SCTK: Parse Python poetry lockfile and manifest

[pombredanne]

See https://github.com/python-poetry/poetry
These are now using pyproject.toml

[AyanSinhaMahapatra]

See https://python-poetry.org/docs/basic-usage/

Example: https://github.com/Tinche/cattrs/blob/master/poetry.lock

[AyanSinhaMahapatra]

This is completed with #3757 and merged, closing this.