Implement alerting based on live queries

[geekflyer]

Hi, first of all - thanks for the great work! I've only discovered this plugin a few days ago but it's a major step forward with regards to Logscale's/Humio's Grafana Integration and I'm delighted that it also supports alerting so we can use Grafana Managed Alerting!

I have a question/proposal re alerting:
Currently when setting up a Grafana Managed alert, the plugin will repeatetly query humio using a static query. Let's say I want to fire an alert if any "500" error occurs and want to know this in close to "realtime" I would set the evaluation interval to 1 minutes and perhaps the query window to 2 or 3 minutes. Now this will fire basically run a humio query once a minute which depending on the query may be rather expensive.

As you probably know Humio also supports Live queries, which are sort of efficient realtime streaming queries that incrementally update. I wonder if it would be possible to use Live queries as foundation to implement alerts? I.e. the plugin could run a single live query in the background and whenever the evaluation interval of grafana managed alerts kicks in, the current result of the live query is being presented. I imagine this would be a lot cheaper and faster than running static queries on a repeated schedule.

This idea is somewhat inspired by how Humio's built in "Alerts" work.