Pivotting a report w/ all columns or goals view is broken

[diosmosis]

If a report is viewed in the All Columns view or the Goals view, and the table is pivotted, the result is incorrect (w/ no data being displayed).

The pivoting itself appears to work (although the resulting datatable is missing the numeral prefixes, which may be expected, I'm not sure). After the pivoting the DataTablePostProcessor::$callbackBeforeGenericFilters function is called which erases all data in the table. The closure that removes the rows is here: https://github.com/piwik/piwik/blob/master/core/Plugin/Visualization.php#L400

[mattab]

If a report is viewed in the All Columns view or the Goals view, and the table is pivotted

Maybe we could improve the Pivot feature and display a Metric selector, that would let user select the metric being pivotted. User could choose between Actions, Actions per visit, Average time on site, Goal 1 Conv rate, etc.

If we don't show the metric selector, then we could just for now "disable" the pivot feature when "All columns" or "Goals" view is selected for a datatable?

[diosmosis]

I think this is a good idea, but I think it's unrelated to the failure.

[mattab]

so as first step and scope of this issue: let's simply disable this view so the bug cannot be triggered ie. "disable" the pivot feature when "All columns" or "Goals" view is selected (we would re-investigate later when working on #4776 )