[WIP] Fmakv2

[campeasb]

First PR for fmakv2 dataset contribution.

I am very new to coding and contributing, so I will probably need extra explanation when correcting all of this.

Some parts of the code come from Stella's work, I changed the metadata to match Yuexuan's one on Zenodo (download link).

About the tests :

• I did first all of those indicated on the contributing section of mirdata documentation.
• Then, (it took me a while) I manadged to make the specific test file for fmakv2 pass.
• When commiting the changes, I noticed dozens and dozens of files were changed and untracked. I think it came from the black command (I am coding on Windows, is it linked?).
• I untracked all of these unwanted changes, to only keep fmakv2 ones.

[magdalenafuentes]

Hey @campeasb thanks for this, could you follow the PR template for adding loaders here?

[stellaywong]

Hi @campeasb,

Thanks for your work on this. However @magdalenafuentes, @genisplaja, I believe this PR should be blocked until #625 is reviewed and merged. That pull request represents the original implementation of FMAK, and it includes contributions from both myself and my collaborator Gandalf Hernandez @gandalfhz

Once PR #625 is merged, we welcome your updates, which can be made by building on top of #625 to preserve the contribution history and maintain proper attribution.

Looking forward to collaborating constructively moving forward.