Allow lower dimensional views on arbitrary dimensioned elements

[philippjfr]

Recent enforcement of the dimensionality of gridded data when passed to an element has caused some issues. In particular it is technically valid to create elements which support arbitrary dimensionality to be given a higher dimensional array but only express indexes only for a subset of those dimensions. Reasons you might want to do this:

1. You want to aggregate the array along the non-declared dimensions
2. The element itself aggregates the data during the plotting step (e.g. stats plots like box-whisker and violin)

Fixes current errors in the doc build.

Fixes holoviz/hvplot#698

[codecov-commenter]

Codecov Report

Merging #5208 (a2fa45f) into master (ed6686c) will decrease coverage by 0.65%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master    #5208      +/-   ##
==========================================
- Coverage   86.75%   86.10%   -0.66%     
==========================================
  Files         298      298              
  Lines       62153    61443     -710     
==========================================
- Hits        53923    52907    -1016     
- Misses       8230     8536     +306     

Impacted Files	Coverage Δ
holoviews/core/data/grid.py	85.88% <66.66%> (-0.63%)	⬇️
holoviews/core/data/xarray.py	88.44% <100.00%> (-0.41%)	⬇️
holoviews/tests/core/data/test_ibisinterface.py	4.26% <0.00%> (-77.44%)	⬇️
holoviews/core/data/ibis.py	24.81% <0.00%> (-55.12%)	⬇️
holoviews/core/data/spatialpandas_dask.py	41.50% <0.00%> (-9.29%)	⬇️
holoviews/core/data/util.py	53.57% <0.00%> (-5.36%)	⬇️
holoviews/core/data/cudf.py	16.31% <0.00%> (-3.69%)	⬇️
holoviews/core/data/spatialpandas.py	10.83% <0.00%> (-3.52%)	⬇️
holoviews/core/pprint.py	48.55% <0.00%> (-2.43%)	⬇️
holoviews/ipython/magics.py	62.60% <0.00%> (-2.15%)	⬇️
... and 94 more

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[jlstevens]

Not all the tests have passed yet but at least one test has passed per platform/python version. The test suite will be run again fully for the 1.14.8 hotfix release anyway and on master. Merging!

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.