adaptation of metaphlan3 parser

[AgnesBaud]

Description

metaphlan3 results are by level -> duplicate informations -> deal with unclassified species + remove duplicates

Definition of Done

• [x] New code is tested with unit tests
• [ ] Documentation has been updated
• [ ] Pull Request has been revised by a maintainer of the project

[khillion]

Also, I forgot but more generally, could you make the code in order to be applied to the other metaphlan parser too?