Pose estimation metrics

[Isalia20]

🚀 Feature

Motivation

Currently torchmetrics doesn't support any metrics for pose estimation, example AP for pose estimation which is used for COCO and reported in all pose estimation code/papers such as:
https://github.com/facebookresearch/sapiens
https://github.com/Tau-J/rtmlib

Pitch

Let's add pose estimation metrics to torchmetrics to make it more feature rich

Alternatives

One alternative for users is to write the metric themselves

I can work on this if agreed

[github-actions]

Hi! Thanks for your contribution! Great first issue!

[SkafteNicki]

@Isalia20 good idea, do you know of any good reference implementations that we can base our implementation on?

[Isalia20]

Probably we can use xtcocotools for it.
https://github.com/jin-s13/xtcocoapi

But I'll look more into it once I start working on it