Legend: Remove legendItem from function signatures
Legend: Remove legendItem from function signatures

* Removed legendItem from the function signatures of drawTexts,
  setupTraceToggle and computeTextDimensions.

plotly/plotly.js,aburato/plotly.js,plotly/plotly.js,iongroup/plotly.js,plotly/plotly.js,etpinard/plotly.js,plotly/plotly.js,etpinard/plotly.js,asolagmbh/plotly.js,iongroup/plotly.js,aburato/plotly.js,asolagmbh/plotly.js,iongroup/plotly.js,etpinard/plotly.js,asolagmbh/plotly.js