cleanup(ex/db/detour): remove state_value

[firestack]

PR for :state_value removal thread #2961 (comment)

[bfauble]

if possible can we try to remove any calls to categorize_detour that aren't happening before an update/create in the DB?

https://github.com/mbta/skate/blob/main/lib/skate/detours/detours.ex#L242
https://github.com/mbta/skate/blob/main/lib/skate/detours/detours.ex#L362

These should be able to just reference the status field instead of needing to calculate from the state.

Then I think we can move the logic of this function to the add_status function used within the Detour.changeset here: https://github.com/mbta/skate/blob/main/lib/skate/detours/db/detour.ex#L65 since any status updates I believe should be persisted and subsequently updated in the status field and available for use wherever needed either in a return response or side effect branching and would limit the surface area for state/prop consistency issue that could arise

[firestack]

if possible can we try to remove any calls to categorize_detour that aren't happening before an update/create in the DB?

Sure yeah! I'd prefer to have that in it's own PR, as this should only be concerned with the :state_value IMO.

See #2967