discontinuous cellwise plots

[chmerdon]

cellwise switch is now handled in 2d Makie scalarplot (isolines are switched off for now, though)

[codecov-commenter]

Codecov Report

Attention: 32 lines in your changes are missing coverage. Please review.

Comparison is base (13785e5) 39.54% compared to head (b8d1d59) 39.03%.

Files	Patch %	Lines
src/makie.jl	37.25%	32 Missing :warning:

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Additional details and impacted files

@@            Coverage Diff             @@
##             main      #22      +/-   ##
==========================================
- Coverage   39.54%   39.03%   -0.52%     
==========================================
  Files          10       10              
  Lines        1970     2001      +31     
==========================================
+ Hits          779      781       +2     
- Misses       1191     1220      +29     

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[j-fu]

I am thinking about the API here.

Some thougts:

• With the techniques at hand we probably can handle: P0, P1, P1broken, and instead of :cellwise we could say e.g. space=:P1broken
• For these three cases we could detect the situation automatically from the length of the func array.
• We might try to be consistent with the vision of a GridVisualizeExtendableFEMBaseExt extension. I think the automatic approch would be consistent with that.

[chmerdon]

Yes, I like that idea! While we are at it we can also do space P2 and P2broken.