Variable size and Full Screen

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Variable Size and Full Screen

Have the heatmap be variable width/height (or at least variable width and square). This functionality will allow a variable width Jupyter Widget https://github.com/ismms-himc/clustergrammer2/issues/2#issuecomment-511046347

Thoughts on Implementing Full Screen Mode

Add button to toggle between full screen and normal view. Have control panel float above the visualization. Maybe make a new WebGL context that is positioned on top of everything else (or maybe make a modal type full screen).