Implement Jaccard Index shortcut for metrics

[Moh-Yakoub]

Fixes #1680

Description:

Adding a Jaccard Index shortcut. https://en.wikipedia.org/wiki/Jaccard_index

It does the same computation as the IoU metric. Adding this shortcut as this is a more common name for the metric that IoU.

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[vfdev-5]

Thanks for the PR @Moh-Yakoub !
I minor thing to fix in the docs
and update the docs: docs/source/metrics.rst

[vfdev-5]

Thanks for the updates @Moh-Yakoub , few more things to update in the docs.

[vfdev-5]

@Moh-Yakoub I removed the type annotations from docstring as it is ongoing work now, see #1665

[vfdev-5]

LGTM!