Remove stocks/disc/cnews command

[piiq]

The bug in the cnews (customized news) command was identified in the integration test logs.
The cnews command that scrapes a seekingalpha page now bumps into a capcha window and does not work any more.

This PR removes the command from the terminal, SDK, translations, default sources json, tests and intros section of the documentation.

I've updated the tests for the controller and the seeking aplha model and view

Note: there were a few duplicate fields in the default_sources.json that I've cleaned up

Question to @jose-donato: Will need to update the default sources section on the hub manually?

[reviewpad]

Reviewpad Report

⚠️ Warnings

• The pyproject.toml file has been changed. Please make sure that the files requirements.txt and requirements-full.txt do not need to be updated

[jmaslek]

[codecov]

Codecov Report

Patch coverage: 57.14% and project coverage change: -0.02 ⚠️

Comparison is base (1444141) 58.28% compared to head (34f2597) 58.27%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4920      +/-   ##
===========================================
- Coverage    58.28%   58.27%   -0.02%     
===========================================
  Files          588      588              
  Lines        53667    53633      -34     
===========================================
- Hits         31280    31253      -27     
+ Misses       22387    22380       -7     

Impacted Files	Coverage Δ
...inal/core/sdk/controllers/stocks_sdk_controller.py	0.00% <ø> (ø)
...penbb_terminal/core/sdk/models/stocks_sdk_model.py	0.00% <ø> (ø)
...minal/cryptocurrency/due_diligence/messari_view.py	24.12% <ø> (+0.12%)	⬆️
...penbb_terminal/stocks/discovery/disc_controller.py	90.66% <ø> (-0.06%)	⬇️
...b_terminal/stocks/discovery/seeking_alpha_model.py	77.02% <ø> (-2.98%)	⬇️
openbb_terminal/terminal_controller.py	17.45% <0.00%> (+0.08%)	⬆️
...terminal/cryptocurrency/defi/cryptosaurio_model.py	87.09% <20.00%> (-5.77%)	⬇️
openbb_terminal/helper_funcs.py	49.69% <33.33%> (+<0.01%)	⬆️
..._terminal/cryptocurrency/defi/cryptosaurio_view.py	91.66% <90.00%> (-3.58%)	⬇️
...bb_terminal/stocks/discovery/seeking_alpha_view.py	71.79% <100.00%> (-3.21%)	⬇️

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