admin/alert-counts: add admin alert counts

[KatieMSB]

• Identified the issue which this PR solves.
• Read the CONTRIBUTING document.
• Code builds clean without any errors or warnings.
• Added appropriate tests for any new functionality.
• All new and existing tests passed.
• Added comments in the code, where necessary.
• Ran make check to catch common errors. Fixed any that came up.

Description:
This pr adds new alert count page under the admin section to display all service alert counts over time. Total, max, and average values for alerts for all services are show in the data table. All services in the current page of the data table are shown in the graph.

Which issue(s) this PR fixes:
Closes #2475

Screenshots:

[mastercactapus]

This has come along well, I like the colors, and it keeps the page rendering smoothly. When I tested it a couple of things I noticed:

• Seems like there should be some sort of loading state when the data is stale/still loading
• Can we have the X-axis labels account for the selected duration (e.g., daily show the day but not hour:minute)
• Is it possible to limit labels with the graph we have selected (e.g., show tick marks but only label every x values)

The last two are probably nice to have to reduce noise

[Forfold]

@mastercactapus I created the issue for the graphs loading here #2519 since ill need to solve that in the message logs graph pr as well

[Forfold]

🎉 🎉 🎉