Alerts dialog issues

[ericpgreen2]

From this Slack message:

The Alerts dialog has some funky behaviour that can block the user from using it, especially if you split the data by a high cardinality field.

• For certain time ranges, the metric total doesn't match the real figure when certain time ranges are selected. I tried Today, Yesterday, Last 1 Week.
• The sample figures are sorted in ascending order, which means for high cardinality fields you only see a bit of the long tail instead of the largest dimensions. Descending order with significant values first would work better.
  • Also, when trying to set criteria, it means that no data appear to meet even a low threshold
• The options to alert based on changes are greyed out, even when starting with a comparison period selected
• Not a bug but: it would be useful to be able to change the time period from within the alert dialog, especially when reacting to the tooltip if you started the dialog without a comparison period selected..

Tested on this dashboard.