[WIP] Make benchopt.clian executable module

[rflamary]

This PR aim at alowing calling benchopt from any python interpreter with something like

python -m benchopt.cli

Basically we just need to add a file in the cli module

I find this interesting because it allow to run benchopt from different environments without the need to activate them. Similar feature are available for pytest and pip

Checks before merging PR

• added documentation for any new feature
• added unit test
• edited the what's new (if applicable)

[codecov-commenter]

Codecov Report

Merging #685 (6e48171) into main (fd0a016) will decrease coverage by 0.02%.
The diff coverage is 0.00%.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #685      +/-   ##
==========================================
- Coverage   55.03%   55.01%   -0.02%     
==========================================
  Files          45       46       +1     
  Lines        2962     2963       +1     
  Branches      548      548              
==========================================
  Hits         1630     1630              
- Misses       1209     1210       +1     
  Partials      123      123