Create notices and circulars for medium-latency GRB detections

The GRB group has requested that we support both notices (GCN, I assume Kafka as well) and circulars concerning medium-latency pipelines that follow up GRBs (could be detection or non-detection).

Circulars:

• There is currently code that produces these circulars but could be out-of-date, so need to ensure these are ready for O4 or update them accordingly (see this issues: ligo-followup-advocate#68 (closed))

Notices:

• Identify whether these notices should be created automatically or require human vetting (similar to how we send update notices via the dashboard: https://emfollow.ligo.caltech.edu/gwcelery/)
• Identify what conditions to create a notice (both detection and non-detection), i.e. what information/labels need to present in an external event or superevent to identify a notice should be sent
• Identify any additional fields or info not currently included in our alerts (both GCN and Kafka) that need to be added: https://emfollow.docs.ligo.org/userguide/content.html

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• Once we've identified the scope, we can start to work out between external_triggers.py, alerts.py, views.py, and GraceDB what needs to be developed.