[WIP] Adding torch ccl backend

[Moh-Yakoub]

Fixes #1728

Description:

This is a WIP to have a discussion about the support of CCL backend, this is my first backend implementation so I'm expecting it will need couple of iterations before it's fully complete.

Few points to discuss as well

1. Given the way we define the ccl, does it make sense to just add it as a supported backend in the native computation model as both implementation are pretty much identical?

Notes:

• Mypy is likely to fail as I haven't installed the torch-ccl yet.
• Once I collect feedback on the approach, I will implement a set of tests for that backend.

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]

@Moh-Yakoub thanks for the PR !

Let's try to write a small use-case example at first and then we'll see what do we need and the blockers...