Add the ability to filter on EduGAIN entities

[phavekes]

This issue is imported from pivotal - Originaly created at Apr 5, 2019 by Bart Geesink

We'd like to be able to filter on EduGAIN entities to gather EduGAIN statistics.

[phavekes]

@bartgeesink Does the filter needs to look at "metaDataFields.coin:publish_in_edugain" in combination with "coin:publish_in_edugain_date" if present? For both IdP and SP? (Okke Harsta - May 17, 2019)

[phavekes]

@bartgeesink For the group_by view it is trivial to filter out the IdP\'s or SP\'s that are published in eduGAIN. For the aggregated view it is more work as we need to change the influxDB query to include the correct providers like we do with institution type. See https://github.com/OpenConext/OpenConext-statistics/blob/master/server/influx/repo.py#L105

Do we want to support the published in eduGAIN for IdP's or SP's or both? In the latter case we need two filters. "SP's published in eduGAIN" and "IdP's published in eduGAIN" (Okke Harsta - May 17, 2019)

[phavekes]

I'll discuss this internally and get back to you on that
(Bart Geesink - May 17, 2019)

[phavekes]

FWIW, we collect no stats for SP's published in eduGAIN.

I think it makes more sense to discard the notion of looking at "published_in_edugain" but instead focus on entities with "interfed_source: eduGAIN" (Thijs Kinkhorst - Jun 24, 2022)