Add cocotb tests

[M0stafaRady]

Adding files needed for cocotb flow to run.
Added tests.

[marwaneltoukhy]

Is this going to replace the current flow? If so, can you remove everything that has to do with the current flow, especially from the documentation, and add the link on how to add cocotb tests in the quick start.

I have a few requests:

1. Installation and run commands should be part of the quick start, even if it's in the readthedocs.
2. I think you should release it on PyPi, to install it using pip not cloning and installing locally.
3. Installation of cocotb infrastructure should be part of make setup.
4. RTL and GL verification should run in the CI, just like the old setup.

If you need help with the last two point please let me know.