fix: HeatmapLayer working with binary data

[felixpalmer]

Fix needed for geoarrow/deck.gl-layers#133

Background

The HeatmapLayer does not currently work when data is passed in binary format (as needed by lonboard) as the buffer layout on the weights transform is not correct

Example to repro, included in this PR: 887aefe

Change List

• Fix bug (by recreating weightsTransform whenever the data prop is changed
• Remove use of setTexture2DData(...) as luma no longer allows this
• Reinstate heatmap tests
• Add new test to verify binary data buffer layouts are now correct

[kylebarron]

Thank you! I'm not knowledgeable of HeatmapLayer internals, so I'm not the best reviewer, but I'm excited to see this in Lonboard

[coveralls]

coverage: 91.113% (+0.009%) from 91.104%
when pulling de108ce on felix/heatmap-binary-attributes
into c3b8e28 on master.