In jqplot.js for CoreVisualizations plugin this.param.viewDataTable should have values described in some configuration #8091

At the moment if I want to check if this.param.viewDataTable is of some kind i have to hard code types into code. Checking against some configuration would leave code more flexible.

FYI the possible values are graphVerticalBar, graphEvolution, graphPie, cloud, table, sparkline, tableAllColumns. The values can be found in the Visualisations classes in the const field ID eg. https://github.com/piwik/piwik/blob/master/plugins/CoreVisualizations/Visualizations/JqplotGraph/Bar.php#L20-20

Maybe we could document these values somewhere (not sure where?)