[jessiethw]

The main goal of this PR is to update the sender script (combine_results_kafka) to use the GCN-Kafka LVK GCNs. It also updates the format of the lvk_nu_track_search stream to match the associated updates to our schema. It is ready for review, but will continue to have updates as preparations for the run continue.

Changes

• Update parameter fields to match LVK GCN-Kafka GCNs
• Update fields in new GCN schema format
• Change to python-dotenv for handling env variables
• Remove outdated run_2week_gw_followup.py script
• Add __init__.py for slack poster utilities so that docs can make properly

[physics-png]

looks good overall, some minor comments and suggestions

[physics-png]

looks great thnx for addressing comments quickly

[jessiethw]

GCN PRs are approved and likely will be merged soon. @physics-png I am going to wait til they're merged, then remove the placeholders and put the actual version once they do the release, rather than doing a fresh PR for this

[jessiethw]

@physics-png GCN has the new schema release, so I've added that. This should be ready to merge now, whenever you approve!