fix: Minor recording rule registry fixes

fix: No double recording rules for global search SLI

We were already generating these rules as part of the web service's recording-rule registry. So we don't need them in the API ones.

Notice how the recording rules do not include a type selector, but include the type in the aggregation labels.

fix: add region as a significant label for slis

Some SLIs need to have a region significant label to be able to have that in the aggregated recording rules to be used for regional alerts.

This will make global rules use the recordings from the recording rule registry when possible.