[ENH] Scatter plot: Bring discrete attributes functionality back

[VesnaT]

Issue

Fixes #4385

Description of changes

• revert commit f193420
• revert commit 87b67a8
• apply commit 1418d09

Includes

• Code changes
• Tests
• Documentation

[codecov]

Codecov Report

Merging #5440 (89ed01b) into master (3773093) will increase coverage by 0.20%.
The diff coverage is 97.87%.

@@            Coverage Diff             @@
##           master    #5440      +/-   ##
==========================================
+ Coverage   86.15%   86.35%   +0.20%     
==========================================
  Files         303      304       +1     
  Lines       61606    61652      +46     
==========================================
+ Hits        53074    53240     +166     
+ Misses       8532     8412     -120     

[markotoplak]

It might be a good idea to bump the widget settings version.

Also, jittering continuous attributes is not a parameter; before any amount of jittering applied to continuous features. So to keep the same behavior for saved workflows we should set it to True for old workflows.

[lanzagar]

the second bullet in Description of changes says:

revert commit 3773093

Did you copy the wrong commit hash because that one seems unrelated?

Otherwise I tried it and categorical vars work again 👍

[VesnaT]

@lanzagar yes, the commit was wrong. I fixed that, thanks for noticing.
@markotoplak you are right, thanks for pointing that out. I'll implement the settings migration.