Allow resizing deepscatter canvas

[bmschmidt]

This PR starts implementing resizing a deepscatter plot by calling plot.resize(width, height).

• resize all WebGL buffers
• resize all DOM elements
• adjust bbox of d3.zoom
• ensure scale, get_current_corners() understand the new bbox
• maintain center of viewport on resize, not upper-left.
• Don't drop background color

[bmschmidt]

• Allow resizing deepscatter canvas #81 👈 (View in Graphite)
• no linting in ci #194 : 1 other dependent PR (#192 )
• main

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[RLesser]

Is this ready @bmschmidt ? would be nice to have