Support *.mol files

[PaulWAyers]

@vcanogil suggested that we should also support a *.mol file.

Links to the detailed file specification are below, but this should be very easy I think, because we already support a *.sdf file.

• https://chem.libretexts.org/Courses/University_of_Arkansas_Little_Rock/ChemInformatics_(2017)%3A_Chem_4399_5399/2.2%3A_Chemical_Representations_on_Computer%3A_Part_II/2.2.2%3A_Anatomy_of_a_MOL_file

• https://docs.chemaxon.com/display/docs/mdl-molfiles-rgfiles-sdfiles-rxnfiles-rdfiles-formats.md

• https://en.wikipedia.org/wiki/Chemical_table_file

[nwoodweb]

Hi @PaulWAyers
I am currently working on this issue

While I do have a functioning load_one at this moment, I am working to see how I can go about parsing charges from the atom block

[FarnazH]

@nwoodweb thanks for working on this issue. Please follow our contributing guidelines https://iodata.readthedocs.io/en/latest/contributing.html in preparing your PR.

[nwoodweb]

@FarnazH

I wanted to inform you that I had passed the Roberto CI check and I will be making a pull request.
While I have implemented an iodata/formats/mol.py file, I have not implemented a test file that other format files had according to Roberto and I was wanting to know if I should also implement this.