Feature Suggestion: District View menu

[CErratum]

While EDS is a great tool, it can be difficult to see if a district is being served by a service building - as I have discovered several times when a new district has burnt down. A basic District View menu would make it much easier to assign service buildings.

Rough layout suggestion:

The "Filter Menu" should have some basic filters - ability to filter by building type, whether the building is inside the selected district, whether it's assigned to the district, and whether it's on / off / has a status condition (e.g., power plant out of fuel, landfill full). Ability to search by building name might also be useful.

The Building Details panel could be the same elements as the default per-building EDS menu, though a button to quickly assign selected building(s) to the active district would be super useful as well.