fixes CNVS-28890, CNVS-28891
including auto-refresh, and optimizations for InCommon
test plan:
* use a metadata URI to configure a SAML provider;
everything should populate
* have your IdP change their metadata, then wait a day
for the periodic job, or manually run
AccountAuthorizationConfig::SAML::MetadataRefresher.refresh_providers
* it should be updated automatically
* set the URI to urn:mace:incommon, and fill in a entity id
of a school in InCommon
* it should populate automatically
Change-Id: Ie508483da2ffa81dce3b98dbd5ae5c0b9e2ac878
Reviewed-on: https://gerrit.instructure.com/76989
QA-Review: Jeremy Putnam <jeremyp@instructure.com>
Reviewed-by: Rob Orton <rob@instructure.com>
Tested-by: Jenkins
Product-Review: Cody Cutrer <cody@instructure.com>