scattergl lines don't show up under select/lasso drag modes

[etpinard]

See https://codepen.io/etpinard/pen/ddZxmy?editors=0010

Originally reported in https://community.plot.ly/t/data-disappears-on-box-select/8392

cc @dfcreative

[alexcjohnson]

Also the modebar icons for box & lasso select don't show up with mode: 'lines' regardless of whether you've set yourself in one of those modes or not.

[dy]

@etpinard will be fixed in https://github.com/plotly/plotly.js/tree/regl-scatter-patch