Add dark Signal Montior

[Charlie-Henry]

Specs in here: https://github.com/cityofaustin/atd-data-tech/issues/15212

This PR is adding an additional signal status (dark) to the socrata backend of this page.

Steps to test:

• Currently, you have to run the code in the atd-kits PR in order to populate the dark signal that has been set for testing purposes at Cameron/Ferguson. The current airflow DAG runs every 5 minutes and will remove that dark signal from the dataset if you aren't quick enough.
• npm run dev and check the signal monitor for the dark signal.

Here's what it looks like:

Popup:

[Charlie-Henry]

@ChristinaTremel could you verify what the wording should be. Dark could be somewhat confusing but idk how else to word it.

[ChristinaTremel]

Here's the feedback from Lance:

• Could we size up the dark signal symbol and change it to the signal that has the line through it?
  • If we still don't like the dark symbol, we could change to the red triangle
• Wants to keep Scheduled Flash the same, but likes the idea of changing the Unscheduled Flash to the same orange or yellow so it doesn't look so urgent

And then he said "ultimately if we go-live and change symbology later, I'm cool with that. don't want to hold it up over aesthetics that we can potentially change later if that isn't too much trouble"

So this being said, we should ship it, but we can make changes in the future! 🚢

[Charlie-Henry]

@ChristinaTremel @johnclary, updated to use TrafficLightsOff instead. I like the idea of l go-live this weekend and change it later!

[Charlie-Henry]

made an issue here for this tech debt https://github.com/cityofaustin/atd-data-tech/issues/15250