Clean up feature flags

[cythrawll]

Is your feature request related to a problem? Please describe. Too many feature flags, most we'll never toggle again.

Describe the solution you'd like Review each feature flag and remove ones that are no longer necessary

[cythrawll]

• [ ] enableTableEditing -- don't need
• [ ] enableVerticalCollectionTableIterator -- don't need
• [x] enableChartStacking -- don't need (#570)
• [ ] enableMultipleExport -- change to support pdf export
• [ ] enableTotals -- keep (need for non additive metrics)
• [ ] dashboards -- move to a check for dashboard addon
• [ ] dateDimensionFilter -- don't need
• [ ] newDimensionSearchAPI -- keep
• [x] enableDirectory -- move to a check for the directory addon
• [ ] enableDashboardExport -- change to support pdf export
• [ ] enableScheduleDashboards -- keep
• [ ] enableDashboardFilters -- check with @colemanProjects
• [ ] enableContains -- don't need