several changes needed to the "raw signals" panel

- It's too slow to load.
- I'm sure we can speed the code up but in the meantime we should switch from 100 entities displayed to maybe 10 or 20
- A user should be able to get to another panel or page with the stacked horizon charts for just one data source. This panel would use more vertical space and would still have the table to allow the user to (de)select entities
- The delay mechanism on the selection checkboxes doesn't work. I.e., if you try to uncheck many boxes it will start loading in the middle and ignore some of the check/uncheck the user made
- As mentioned in issue #10, sorting the table by number of IPs is broken