Expand filtering options for related resource pairs in /api/events/filter

[ogenstad]

Describe the current behavior

When using /api/events/filter it's possible to match against related resources using the EventFilter object in JSON format. The EventRelatedFilter object allows us to filter the events based on a set of keys and values contained within an related resource where all fields are expected to match a related resource.

Describe the proposed behavior

It would be great if there was an additional option to search and match against multiple pairs at once.

The filter, could then be expanded with an additional attribute looking something like this:

class EventRelatedFilter(EventDataFilter):
    label_pairs: Optional[List[ResourceSpecification]] = Field(
        None, description="Only include events for related resources with these label pairs"
    )

Example Use

Posting to the new API might look like this:

{
  "filter": {
      "related": {
          "label_pairs": [
              {
                  "prefect.resource.role": "department",
                  "prefect.resource.id": "develop"
              },
              {
                "prefect.resource.role": "environment",
                "prefect.resource.id": "test"
            }
          ]
      }
  }
}

The above would return all events that had a combination of the related resources.

Additional context

Note this is somewhat related to #16978 and a similar operator selection as described there would also be useful.