Bug in FEEC bases constructor

[JordiManyer]

@Antoinemarteau I think this is yours. Maybe we should add more extensive tests for these constructors. See also gridap/GridapEmbedded.jl#120

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.69%. Comparing base (7f2ce32) to head (0eedd7d).
⚠️ Report is 7 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1260      +/-   ##
==========================================
- Coverage   88.69%   88.69%   -0.01%     
==========================================
  Files         226      226              
  Lines       29245    29244       -1     
==========================================
- Hits        25940    25939       -1     
  Misses       3305     3305              

Flag	Coverage Δ
drivers	39.85% <50.00%> (+<0.01%)	⬆️
extensions	5.24% <0.00%> (+<0.01%)	⬆️
unit-adaptivity	37.41% <0.00%> (+<0.01%)	⬆️
unit-basics	13.82% <0.00%> (+<0.01%)	⬆️
unit-celldata	21.43% <0.00%> (+<0.01%)	⬆️
unit-fespaces-1	32.75% <100.00%> (-0.01%)	⬇️
unit-fespaces-2	39.28% <50.00%> (+<0.01%)	⬆️
unit-fields	17.74% <50.00%> (+<0.01%)	⬆️
unit-geometry	29.26% <0.00%> (+<0.01%)	⬆️
unit-multifield	31.34% <50.00%> (+<0.01%)	⬆️
unit-odes	29.18% <0.00%> (+<0.01%)	⬆️
unit-referencefes	34.76% <100.00%> (-0.01%)	⬇️
unit-visualization	12.12% <0.00%> (+<0.01%)	⬆️

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[Antoinemarteau]

My bad. The bug was in the caller of FEEC_poly_basis though. I checked all the calls, they should be fine now.
I clarified the error message given by FEEC_poly_basis.