Heatmap: don't reload if the taxon level doesn't actually change (#910)
Heatmap: don't reload if the taxon level doesn't actually change (#910)

* Add loading icon

* Don't reload data if taxon level doesn't actually change

chanzuckerberg/idseq-web,chanzuckerberg/idseq-web,chanzuckerberg/idseq-web,chanzuckerberg/idseq-web,chanzuckerberg/idseq-web