NWS alert identifiers structure appears to have changed meaningfully recently

[amvtek]

Describe the bug
We have an etl that loads NWS alerts from the https://api.weather.gov/alerts endpoint.
We have observed failure in the recent days (after 2021-02-24) which are related to changes in alert identifier structure.

Before 2021-02-24 alert identifiers were as described in your api openapi schema (AlertId component):

• eg NWS-IDP-PROD-4690566-3817270

Now it looks a different structure is used

• eg urn:oid:2.49.0.1.840.0.d9e2ee087e47de883a903df33ed0ff603f3ace1a.001.1

This new structure does not match current AlertId component in openapi schema.

To Reproduce
Pull alerts using the ``https://api.weather.gov/alerts` endpoint in geo json format and checks the id field

Expected behavior
Identifier structure shall be documented and a maximum size should be set.

[StephenClouse]

This was an announced service change:

https://www.weather.gov/media/notification/pdf2/scn21-01cap_handler_v2aab.pdf

I have not uploaded the updated OpenAPI schema since adjusting for this change. I will do this later today.