Per agreement in NYC sprint, add status check is_active to table

https://docs.google.com/document/d/1z1Lm-DUrri6xPzGXU37nLk5SfRjo4i9Elvx-lfbmK24/edit#heading=h.164d9ulc2oa3

added Concept approved ~332 triaged type:proposal labels

mentioned in commit 8632e9d7

changed milestone to %5.20.0

closed

https://github.com/civicrm/civicrm-core/pull/15409

This means a specific check can be disabled site-wide like this

 $this->callAPISuccess('StatusPreference', 'create', [
      'name' => 'checkDefaultMailbox',
      'is_active' => 0,
    ]);

This was agreed to only be exposed through the api - we don't want a UI user to be able to suppress an alert site wide.

mentioned in issue #1327 (closed)