Improve efficiency of image viewer when using dask arrays

[astrofrog]

This is an alternative to #2136 and I find it cleaner since it is consistent with the conceptual behavior for non-dask arrays, and doesn't change anything for non-dask arrays.

More work is needed to make glue fully benefit from dask arrays, but this is a start.

[codecov]

Codecov Report

Merging #2137 into master will decrease coverage by 0.10%.
The diff coverage is 51.06%.

@@            Coverage Diff             @@
##           master    #2137      +/-   ##
==========================================
- Coverage   87.99%   87.88%   -0.11%     
==========================================
  Files         245      245              
  Lines       22322    22409      +87     
==========================================
+ Hits        19642    19695      +53     
- Misses       2680     2714      +34     

Impacted Files	Coverage Δ
glue/utils/array.py	89.49% <10.52%> (-5.86%)	⬇️
glue/core/fixed_resolution_buffer.py	88.52% <50.00%> (-6.12%)	⬇️
glue/core/data.py	91.37% <57.14%> (+0.26%)	⬆️
glue/core/component.py	91.28% <59.45%> (-5.78%)	⬇️
glue/core/data_factories/helpers.py	93.01% <100.00%> (+0.07%)	⬆️
glue/core/link_manager.py	97.64% <100.00%> (ø)
glue/plugins/coordinate_helpers/link_helpers.py	100.00% <100.00%> (ø)
glue/core/state.py	92.09% <0.00%> (+0.03%)	⬆️
glue/viewers/image/state.py	91.07% <0.00%> (+0.05%)	⬆️
glue/config.py	85.32% <0.00%> (+0.44%)	⬆️
... and 2 more

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